JACC: Cardiovascular Interventions

A Percutaneous Treatment Algorithm for Crossing Coronary Chronic Total Occlusions

2012-04-01

Coronary chronic total occlusions (CTOs) are frequently identified during coronary angiography and remain the most challenging lesion group to treat. Patients with CTOs are frequently left unrevascularized due to perceptions of high failure rates and technical complexity even if they have symptoms of coronary disease or ischemia. In this review, the authors describe a North American contemporary approach for percutaneous coronary interventions for CTO. Two guide catheters are placed to facilitate seamless transition between antegrade wire–based, antegrade dissection re-entry–based, and retrograde (wire or dissection re-entry) techniques, the “hybrid” interventional strategy. After dual coronary injection is performed, 4 angiographic parameters are assessed: 1) clear understanding of location of the proximal cap using angiography or intravascular ultrasonography; 2) lesion length; 3) presence of branches, as well as size and quality of the target vessel at the distal cap; and 4) suitability of collaterals for retrograde techniques. On the basis of these 4 characteristics, an initial strategy and rank order hierarchy for technical approaches is established. Radiation exposure, contrast utilization, and procedure time are monitored throughout the procedure, and thresholds are established for intraprocedural strategy conversion to maximize safety, efficiency, and effectiveness.

Successful Recanalization of Chronic Total Occlusions Is Associated With Improved Long-Term Survival

2012-04-01

Objectives: This study investigated the impact of procedural success on mortality following chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in a large cohort of patients in the drug-eluting stent era. Background: Despite advances in expertise and technologies, many patients with CTO are not offered PCI. Methods: A total of 6,996 patients underwent elective PCI for stable angina at a single center (2003 to 2010), 836 (11.9%) for CTO. All-cause mortality was obtained to 5 years (median: 3.8 years; interquartile range: 2.0 to 5.4 years) and stratified according to successful chronic total occlusion (sCTO) or unsuccessful chronic total occlusion (uCTO) recanalization. Major adverse cardiac events (MACE) included myocardial infarction (MI), urgent revascularization, stroke, or death. Results: A total of 582 (69.6%) procedures were successful. Stents were implanted in 97.0% of successful procedures (mean: 2.3 ± 0.1 stents per patient, 73% drug-eluting). Prior revascularization was more frequent among uCTO patients: coronary artery bypass grafting (CABG) (16.5% vs. 7.4%; p < 0.0001), PCI (36.0% vs. 21.2%; p < 0.0001). Baseline characteristics were otherwise similar. Intraprocedural complications, including coronary dissection, were more frequent in unsuccessful cases (20.5% vs. 4.9%; p < 0.0001), but did not affect in-hospital MACE (3% vs. 2.1%; p = NS). All-cause mortality was 17.2% for uCTO and 4.5% for sCTO at 5 years (p < 0.0001). The need for CABG was reduced following sCTO (3.1% vs. 22.1%; p < 0.0001). Multivariate analysis demonstrated that procedural success was independently predictive of mortality (hazard ratio [HR]: 0.32 [95% confidence interval (CI): 0.18 to 0.58]), which persisted when incorporating a propensity score (HR: 0.28 [95% CI: 0.15 to 0.52]). Conclusions: Successful CTO PCI is associated with improved survival out to 5 years. Adoption of techniques and technologies to improve procedural success may have an impact on prognosis.

Percutaneous Revascularization of Chronic Total Coronary Occlusions: Are the Benefits Underappreciated?⁎

Jeffrey W. Moses, Dimitri Karmpaliotis — 2012-04-01

Chronically totally occluded coronary arteries (CTOs) are common and represent the most technically challenging subset of lesions in contemporary interventional cardiology (). The presence of a CTO on coronary angiography has a powerful impact on treatment decisions, leading to more frequent referral to coronary artery bypass grafting (CABG) and medical therapy when compared with when only stenotic lesions are present.

Use of a Novel Crossing and Re-Entry System in Coronary Chronic Total Occlusions That Have Failed Standard Crossing Techniques: Results of the FAST-CTOs (Facilitated Antegrade Steering Technique in Chronic Total Occlusions) Trial

2012-04-01

Objectives: This study sought to examine the efficacy and safety of 3 novel devices to recanalize coronary chronic total occlusions (CTOs). Background: Successful percutaneous coronary intervention (PCI) of CTOs improves clinical outcome in appropriately selected patients. CTO PCI success, however, remains suboptimal. Methods: A new crossing catheter and re-entry system was evaluated in a prospective, multicenter, single-arm trial of CTO lesions refractory to standard PCI techniques. The primary efficacy endpoint was the frequency of true lumen guidewire placement distal to the CTO (technical success). Results: Enrollment included 147 patients with 150 CTOs. The mean lesion length was 41 ± 17 mm. A crossing catheter crossed 56 lesions into the distal true lumen, and a re-entry catheter facilitated tapered-wire cannulation of the distal lumen in 59 CTOs initially crossed subintimally (77% technical success). Success in the first 75 CTOs was 67%, rising to 87% in the last 75 CTOs. Mean fluoroscopy and procedure times were 45 ± 16 min and 90 ± 12 min, respectively, each significantly shorter than in historical controls (p < 0.0001 for both). Coronary perforation occurred in 14 cases (9.3%), requiring treatment in 3 cases (prolonged balloon inflation, with additional coil embolization in 1 case). No tamponade or hemodynamic instability occurred. Six patients had periprocedural non–ST-segment elevation myocardial infarction. No emergency surgery, ST-segment elevation myocardial infarction, or cardiac reintervention occurred. Two deaths occurred within 30 days, neither as a direct result of the procedure. The 30-day major adverse cardiac event rate was 4.8%. Conclusions: In CTOs failing standard techniques, use of a new crossing and re-entry system results in a high success rate without increasing complications.

Maximal Hyperemia in the Assessment of Fractional Flow Reserve: Intracoronary Adenosine Versus Intracoronary Sodium Nitroprusside Versus Intravenous Adenosine: The NASCI (Nitroprussiato Versus Adenosina nelle Stenosi Coronariche Intermedie) Study

2012-04-01

Objectives: This study sought to compare increasing doses of intracoronary (IC) adenosine or IC sodium nitroprusside versus intravenous (IV) adenosine for fractional flow reserve (FFR) assessment. Background: Maximal hyperemia is the critical prerequisite for FFR assessment. Despite IV adenosine currently representing the recommended approach, IC administration of adenosine or other coronary vasodilators constitutes a valuable alternative in everyday practice. However, it is surprisingly unclear which IC strategy allows the achievement of FFR values comparable to IV adenosine. Methods: Fifty intermediate coronary stenoses (n = 45) undergoing FFR measurement were prospectively and consecutively enrolled. Hyperemia was sequentially induced by incremental boli of IC adenosine (ADN) (60 μg ADN60, 300 μg ADN300, 600 μg ADN600), by IC sodium nitroprusside (NTP) (0.6 μg/kg bolus) and by IV adenosine infusion (IVADN) (140 μg/kg/min). FFR values, symptoms, and development of atrioventricular block were recorded. Results: Incremental doses of IC adenosine and NTP were well tolerated and associated with fewer symptoms than IVADN. Intracoronary adenosine doses (0.881 ± 0.067, 0.871 ± 0.068, and 0.868 ± 0.070 with ADN60, ADN300, and ADN600, respectively) and NTP (0.892 ± 0.072) induced a significant decrease of FFR compared with baseline levels (p < 0.001). Notably, ADN600 only was associated with FFR values similar to IVADN (0.867 ± 0.072, p = 0.28). Among the 10 patients with FFR values ≤0.80 with IVADN, 5 were correctly identified also by ADN60, 6 by ADN300, 7 by ADN600, and 6 by NTP. Conclusions: Intracoronary adenosine, at doses higher than currently suggested, allows obtaining FFR values similar to IV adenosine. Intravenous adenosine, which remains the gold standard, might thus be reserved for those lesions with equivocal FFR values after high (up to 600 μg) IC adenosine doses.

Relationship Between Fractional Flow Reserve and Angiographic and Intravascular Ultrasound Parameters in Ostial Lesions: Major Epicardial Vessel Versus Side Branch Ostial Lesions

2012-04-01

Objectives: This study sought to assess the relationship of coronary angiography, intravascular ultrasound (IVUS) and fractional flow reserve (FFR) between major epicardial vessel (MV) and side branch (SB) ostial lesions. Background: Evaluation of ostial lesions is clinically very important. However, anatomical parameters have limitations in the prediction of the functional significance of coronary stenoses. Methods: IVUS and FFR measurement were performed in 93 lesions (MV: 38, SB: 55). Optimal angiographic and IVUS criteria and their diagnostic accuracy for functionally significant stenoses (FFR ≤0.8) were assessed. Results: In MV ostial lesions, FFR had correlation with angiographic percent diameter stenosis (r = –0.68, p < 0.001), minimum lumen area (MLA) by IVUS (r = 0.55, p < 0.001), percent plaque burden (r = –0.42, p = 0.011), and percent area stenosis (r = –0.49, p = 0.003). Meanwhile, FFR had no correlation with angiographic percent diameter stenosis (r = –0.067, p = 0.635) and weak correlation with MLA (r = 0.30, p = 0.026) in SB ostial lesions. In MV ostial lesions, best cutoff value of angiographic percent diameter stenosis, MLA, percent plaque burden, and percent area stenosis to determine the functional significance was 53%, 3.5 mm2, 70%, and 50%. However, a statistically significant cutoff value of percent diameter stenosis and MLA could not be found in SB ostial lesions. Conclusions: The relations between angiographic/IVUS parameters and FFR were different between MV and SB ostial lesions. Angiographic and IVUS parameters had poor diagnostic accuracy in predicting the functional significance of SB ostial lesions. (Main Branch Versus Side Branch Ostial Lesion; NCT01335659)

Provoked Exercise Desaturation in Patent Foramen Ovale and Impact of Percutaneous Closure

Ganesh P. Devendra, Ajinkya A. Rane, Richard A. Krasuski — 2012-04-01

Objectives: This study was designed to assess the prevalence of provoked exercise desaturation (PED) in patients with patent foramen ovale (PFO) referred for cardiovascular evaluation and to evaluate the impact of PFO closure. Background: Platypnea orthodeoxia syndrome is a rare, mechanistically obscure consequence of PFO that results in oxygen desaturation during postural changes. In our clinical experience, however, it is far less common than desaturation during exercise. Methods: This was a single-center prospective study of 50 patients with newly diagnosed PFO. Each patient underwent standardized assessment for arterial oxygen saturation with pulse oximetry during postural changes and stair climbing exercise. Provoked exercise desaturation was defined as a desaturation of at least 8% from baseline to <90%. All patients who underwent closure were reevaluated 3 months after the procedure. Those with baseline PED were similarly reassessed for desaturation at follow-up. Results: Mean age of the cohort was 46 ± 17 years, 74% were female, 30% had migraines, and 48% had experienced a cerebrovascular event. Seventeen patients (34%) demonstrated PED. Provoked exercise desaturation patients seemed demographically similar to non-PED patients. Ten PED patients underwent PFO closure (2 surgical, and 8 percutaneous). Drop in oxygen saturation was improved by an average of 10.1 ± 4.2% after closure (p < 0.001), and New York Heart Association functional class improved by a median of 1.5 classes (interquartile range: 0.75 to 2.00, p = 0.008). Conclusions: One-third of patients referred for assessment of PFO experience oxygen desaturation during stair exercise. Closure of PFO seems to ameliorate this phenomenon and improve functional status.

Some Air for Closure of the Patent Foramen Ovale⁎

Bernhard Meier — 2012-04-01

The patient is 56 years old. He likes sports, in particular deep-sea diving. After 2 decompression incidents, he was worked up by a cardiologist and a patent foramen ovale (PFO) was found. Incidentally, he mentioned that he has been increasingly short of breath during physical exercise. The PFO was closed () in an outpatient procedure, and the next day, already, he enjoyed an improved exercise capacity when jogging. This effect proved to be sustained and diving has remained uneventful since.

Risk Factors and Outcomes of Post-Procedure Heart Blocks After Transcatheter Device Closure of Perimembranous Ventricular Septal Defect

2012-04-01

Objectives: The aim of this study was to analyze the risk factors and mid-term outcomes associated with post-procedure heart blocks (PPHBs) after transcatheter closure of perimembranous ventricular septal defect (pmVSD). Background: The development of heart blocks remains a major challenge for transcatheter closure of pmVSD. Methods: Transcatheter closure of pmVSD was carried out in 228 patients. Electrocardiography and 24-h Holter monitoring were performed before the procedure, within 1 week after the procedure, then 1, 3, 6, and 12 months, and every year thereafter. Results: Thirty-three patients (14.5%) who received transcatheter closure of pmVSD developed PPHBs. PPHBs included right bundle branch block (57.6%), left bundle branch block (24.2%), and atrioventricular block (18.2%). High-degree atrioventricular blocks occurred in 4 patients and recovered to normal conduction after intravenous administration of hydrocortisone. PPHBs recovered to normal conduction in 21 patients by the time of hospital discharge. Compared with the patients without PPHBs, the patients suffering PPHBs were characterized by a significantly longer distance between the aortic valve and the defect (DAVD), a shorter distance from the lower rim of the defect to the septal leaflet of the tricuspid valve (DLRD-SLTV), and a larger diameter difference between the occluder and ventricular septal defect (DDOV). The earlier the PPHBs developed after the procedure, the more difficult the recovery to normal conduction. Conclusions: The outcome of PPHBs after transcatheter closure of pmVSD was satisfactory, as most patients recovered to normal conduction. Measurements of DLRD-SLTV, DAVD, and DDOV may be useful in predicting the incidence of PPHBs.

Differences in Neointimal Thickness Between the Adluminal and the Abluminal Sides of Malapposed and Side-Branch Struts in a Polylactide Bioresorbable Scaffold: Evidence In Vivo About the Abluminal Healing Process

2012-04-01

Objectives: The goal of this study was to describe the neointimal healing on the abluminal side (ABL) of malapposed (ISA) struts and nonapposed side-branch (NASB) struts in terms of coverage by optical coherence tomography (OCT) and in comparison with the adluminal side (ADL). Background: The neointimal healing on the ABL of ISA and NASB struts has never to our knowledge been explored in vivo and could be involved in the correction of acute malapposition. The bioresorbable vascular scaffold (BVS) is made of a translucent polymer that enables imaging of the ABL with OCT. Methods: Patients enrolled in the ABSORB B (ABSORB Clinical Investigation Cohort B) study were treated with implantation of a BVS and imaged with OCT at 6 months. Thickness of coverage on the ADL and ABL of ISA and NASB struts was measured by OCT. Results: Twenty-eight patients were analyzed; 114 (2.4%) struts were malapposed or at side branches. In 76 ISA struts (89.4%) and 29 NASB struts (100%), the thickness of ABL coverage was >30 μm. Coverage was thicker on the ABL than on the ADL side (101 vs. 71 μm; 95% confidence interval [CI] of the difference: 20 to 40 μm). In 70 struts (60.7%, 95% CI: 50.6% to 70.0%), the neointimal coverage was thicker on the ABL, versus only 20 struts (18.5%, 95% CI: 11.6% to 28.1%) with thicker neointimal coverage on the ADL side (odds ratio: 3.35, 95% CI: 2.22 to 5.07). Conclusions: Most of the malapposed and side-branch struts are covered on the ABL side 6 months after BVS implantation, with thicker neointimal coverage than on the ADL side. The physiological correction of acute malapposition involves neointimal growth from the strut to the vessel wall or bidirectional. (ABSORB Clinical Investigation, Cohort B [ABSORB B]; NCT00856856)

Nobori Stent Shows Less Vascular Inflammation and Early Recovery of Endothelial Function Compared With Cypher Stent

2012-04-01

Objectives: The current study sought to examine inflammation at the stented segments of Nobori (Terumo Corporation, Tokyo, Japan) and Cypher (Cordis, Miami, Florida) drug-eluting stents (DES), as well as free radical production and endothelial function of the adjacent nonstented segments in a pig coronary model. Background: Nobori is a novel DES, incorporating a biolimus A9-eluting biodegradable polymer coated only on the abluminal surface of the stent. These unique features may favorably affect inflammation and endothelial function, as compared to the currently marketed DES. Presently, pre-clinical data on direct comparison of the various generations of DES are not available. Methods: A total of 18 DES were implanted in pig coronary arteries and subsequently explanted at 1 month. Stented segments were assessed by angiography and histology. Ex vivo vasomotor function and superoxide production in segments proximal and distal to the stent were determined. The vasoconstriction, endothelial-dependent relaxation, and endothelial-independent relaxation of proximal and distal nonstented segments were measured. Results: Histological evaluation revealed lower inflammatory response with Nobori than with Cypher DES. There is trend for lower angiographic percentage diameter stenosis in Nobori versus Cypher groups (p = 0.054). There was increased endothelium-dependent relaxation, decreased endothelin-1–mediated contraction, and less superoxide production in the vessel segments proximal and distal to Nobori versus Cypher stents. Conclusions: Our data show significantly lower inflammatory response in the stented segments, and rapid recovery of endothelial function of peristent segments in the Nobori group compared with Cypher DES group at 1 month in porcine coronary artery model.

Reduction of Operator Radiation Dose by a Pelvic Lead Shield During Cardiac Catheterization by Radial Access: Comparison With Femoral Access

Helmut W. Lange, Heiner von Boetticher — 2012-04-01

Objectives: This study sought to determine the efficacy of patient pelvic lead shielding for the reduction of operator radiation exposure during cardiac catheterization via the radial access in comparison with the femoral access. Background: Cardiac catheterization via the radial access is associated with significantly increased radiation dose to the patient and the operator. Improvements in radiation protection are needed to minimize this drawback. Pelvic lead shielding has the potential to reduce operator radiation dose. Methods: We randomly assigned 210 patients undergoing elective coronary angiography by the same operator to a radial and femoral access with and without pelvic lead shielding of the patient. Operator radiation dose was measured by a radiation dosimeter attached to the outside breast pocket of the lead apron. Results: For radial access, operator dose decreased from 20.9 ± 13.8 μSv to 9.0 ± 5.4 μSv, p < 0.0001 with pelvic lead shielding. For femoral access, it decreased from 15.3 ± 10.4 μSv to 2.9 ± 2.7 μSv, p < 0.0001. Pelvic lead shielding significantly decreased the dose-area product–normalized operator dose (operator dose divided by the dose-area product) by the same amount for radial and femoral access (0.94 ± 0.28 to 0.39 ± 0.19 μSv × Gy−1 × cm−2 and 0.70 ± 0.26 to 0.16 ± 0.13 μSv × Gy−1 × cm−2, respectively). Conclusions: Pelvic lead shielding is highly effective in reducing operator radiation exposure for radial as well as femoral procedures. However, despite its use, radial access remains associated with a higher operator radiation dose.

Amplatzer Septal Occluder Sealed the Complicating Aortic Root Perforation During Transseptal Procedure

Beny Hartono, Omar Abdul Razakjr, Muhammad Munawar — 2012-04-01

An octogenarian man with severe rheumatic mitral stenosis underwent percutaneous transvenous mitral commissurotomy. The procedure was complicated by accidental unrecognized aortic root puncture by Brockenbrough needle followed by the delivery of the 8-F Mullin sheath (Medtronic, Minneapolis, Minnesota). Subsequent contrast injection demonstrated the left coronary artery (A). The complication could be avoided if some cautious procedure were performed, such as measuring the pressure from the Brockenbrough needle to differentiate the left atrial and aortic pressure before advancing the Mullin sheath (Medtronic). We decided to seal the hole with a 4-mm Amplatzer Septal Occluder (ASO) device (St. Jude Medical, St. Paul, Minnesota) instead of surgical intervention. A coiled guidewire (arrow) was advanced to the aorta to facilitate the exchange of the Mullin sheath with an 8-F ASO delivery sheath (B). A test injection of contrast medium confirmed position within aortic root. The loader with the collapsed device was then advanced into the delivery catheter by pushing the delivery cable. Under fluoroscopic and ultrasonic guidance, the ASO device (arrow) was deployed the left atrial disk and pulled gently against the aortic wall, which was both felt and observed by 2-dimensional echocardiography (C). Using gentle tension on the delivery cable, the sheath (arrowhead) was pulled back and the right atrial disk was deployed. Echocardiography and contrast fluoroscopy confirmed optimal position across the communication and the position of the right coronary artery. After release of the ASO (D), both color Doppler echocardiography and angiography performed showed the absence of the residual shunt. During 6-month echocardiographic follow-up, the ASO device remained in place without any residual flow observed. This is the first usage of such a device for a complication that always requires an open-heart surgery (Online Video).

Endovascular Imaging of Angiographically Invisible Spontaneous Coronary Artery Dissection

Fernando Alfonso, Manuel Paulo, Jaime Dutary — 2012-04-01

Spontaneous coronary artery dissection (SCD) is a rare clinical entity (). Clinical diagnosis is challenging and classically relies on the angiographic demonstration of an intimomedial “flap” leading to a double lumen appearance (). Angiography, however, is unable to visualize the coronary wall. New intracoronary diagnostic tools provide comprehensive, tomographic, high-resolution insights on vessel wall pathology, allowing a precise diagnosis of SCD ().

Anterior ST-Segment Elevation Myocardial Infarction in a Patient With an L-I Type Single Coronary Artery

Javed M. Nasir, Karin Hawkins, Gilberto Patino, James Furgerson, Eugene K. Soh — 2012-04-01

These images are from a 51-year-old man who presented to the emergency department with an anterior ST-segment elevation myocardial infarction, Killip class I. During emergency coronary angiography, we were unable to engage the right coronary artery (RCA) with a JR4 catheter (Cordis, Bridgewater, New Jersey) and proceeded to engage the left coronary artery with an XB3.5 guiding catheter (Cordis). The culprit lesion was identified in the mid-left anterior descending artery (LAD), and he underwent successful thrombus aspiration and percutaneous coronary intervention (PCI). Subsequent angiography showed Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 in the LAD, and a dominant left circumflex (LCX) artery that continued in the atrioventricular (AV) groove to supply the RCA distribution. Gated computed tomography (CT) angiography confirmed that this patient had an L-I type single coronary artery. A single coronary artery is a rare anomaly that has been reported in 0.024% to 0.066% of catheterizations (). Angiographic still frames are shown: left anterior oblique (LAO) caudal angiography showing the thrombus occluding the mid LAD (A); right anterior oblique (RAO) caudal, anterior-posterior (AP) cranial, and LAO caudal views, respectively, after PCI showing the LCX continuing to supply the RCA distribution (B to D, Online Videos 1, 2, 3, 4, and 5); and CT angiography of this patient's coronary anatomy (E). Online Video 1 shows LAO caudal angiography pre-PCI. The mid-LAD is thrombotically occluded in the mid-vessel. Online Video 2 shows LAO caudal angiography post-PCI. After PCI, the LAD has TIMI flow grade 3. The LCX artery is seen to continue in the AV groove to supply the RCA distribution. Online Video 3 shows AP cranial angiography post-PCI. The acute marginal and conus branches are also seen arising from the distal LCX artery. Online Video 4 shows RAO caudal angiography post-PCI and the extensive distribution supplied by the LCX artery. Online Video 5 shows rotating cardiac CT angiography. This is a reconstruction from gated CT angiography showing a 3-dimensional representation of this patient's coronary anatomy. Additional cineangiographic images are available online.

Fibromuscular Dysplasia of the Left Anterior Descending Coronary Artery

Gentian Lluri, Tim Provias, Eric H. Yang, Michael S. Lee — 2012-04-01

A 40-year-old man with no known past medical history was admitted for severe depression. A 12-lead electrocardiogram was obtained before electroconvulsive therapy, which revealed ST-segment elevations in V2 to V3. The patient denied any symptoms. Physical examination was unremarkable. Cardiac biomarkers were not elevated. Coronary angiography demonstrated beading of the left anterior descending artery (), suggestive of fibromuscular dysplasia (FMD).

More Positive Fluid Balance Could Explain Lower Risk of Contrast Nephropathy

Veeraish Chauhan — 2012-04-01

The paper by Marenzi et al. () in JACC: Cardiovascular Interventions on prevention of contrast-induced nephropathy (CIN) using furosemide with matched hydration deals with a pertinent and pervasive problem. In this randomized trial of 170 patients who received contrast media during coronary procedures, the investigators compared standard-of-care hydration using intravenous (IV) isotonic saline with furosemide-forced diuresis and IV isotonic saline infusion matched to the urine output. This intervention arm was associated with a lower incidence of CIN (4.6% vs. 18% in control subjects, p = 0.005). However, a crucial piece of data missing in the study, which might confound the results, is the patients' net fluid balance at the end of their respective protocols. Adequate hydration before contrast administration is considered the cornerstone of CIN prevention, although no randomized controlled trial has studied the benefit of hydration alone. It would have added to the validity of the study had the patients' weights been mentioned before and after the protocol because that could be a good surrogate of the patients' net hydration status. Estimation of the net fluid balance based just on the difference between the cumulative IV hydration and the urine outputs shows that patients in the furosemide-matched hydration group were perhaps much better volume repleted than the control subjects were. Patients in the intervention arm received cumulative IV saline volume of 3,995 ± 1,401 ml, with infusion rates matched to the urine output (minus the initial 250-ml IV saline bolus). This indicates an even-to-slightly-positive net fluid balance over the duration of the protocol. The control group, however, received a cumulative IV saline volume of 1,742 ± 290 ml while putting out a urine volume of 3,117 ± 876 ml. This clearly suggests a net negative fluid balance of about 1.3 l. Hence, how much of the final efficacy of furosemide-matched hydration protocol over standard saline hydration in preventing CIN could be attributed to the use of furosemide, versus to the fact that patients in the intervention arm just happened to be much better hydrated, remains debatable. Some of the classic studies that studied volume repletion as a measure to prevent CIN have shown that patients who did better tended to be in an even-to-positive fluid balance, although the results were not always statistically significant ()

Hydration Is Critical for Prevention of Contrast-Induced Nephropathy

Deep Sharma — 2012-04-01

Marenzi et al. () recently reported the results on a single-center, prospective, randomized, nonblinded trial to investigate the role of combined furosemide-induced high-volume diuresis and automated matched hydration (intervention group), combined with standard saline hydration (control group), for the prevention of contrast-induced nephropathy (CIN) in chronic kidney disease patients undergoing coronary procedures.

Reply

Giancarlo Marenzi, Cristina Ferrari, Antonio L. Bartorelli — 2012-04-01

We appreciate the thoughtful comments of Drs. Chauhan and Sharma on our study. We agree with them with regard to the critical importance of generous hydration and positive fluid balance for contrast-induced nephropathy prevention. Current guidelines recommend administration of isotonic electrolyte solutions at an infusion rate of 1.0 ml/kg/h or less (0.5 ml/kg/h) in case of left ventricular ejection fraction <35% or New York Heart Association functional class >2 (). We believe that this hydration rate represents a “safe” regimen conceived for avoiding fluid overload and pulmonary edema rather than an “effective” patient hydration. Indeed, a 70-ml/h hydration rate for 24 h in a 70 kg fasting patient is the minimal fluid volume needed to avoid dehydration. By contrast, vigorous hydration before coronary procedures is difficult logistically and poorly tolerated, in particular in the presence of impaired cardiac and renal function. Thus, despite general agreement on hydration benefit and strong recommendation of all guidelines, most patients are not sufficiently hydrated in routine clinical practice.

Quality Control and the Learning Curve of Transcatheter Aortic Valve Implantation

Alfredo Giuseppe Cerillo, Michele Murzi, Mattia Glauber, Sergio Berti — 2012-04-01

With the introduction of transcatheter valves, the cardiologists and cardiac surgeons have been faced with a new challenge, that is, to keep efficacy and safety competitive in relation to conventional surgery while implementing a new therapeutic strategy that requires the acquisition of new skills and the close cooperation between different specialties. In this complex scenario, the strict monitoring of the overall and individual performance appears mandatory. The paper by Alli et al. (), recently published in JACC: Cardiovascular Interventions, represents a commendable attempt to characterize the learning curve of transcatheter aortic valve implantation (TAVI) in terms of number of procedures needed to become proficient with this technique, and to gain insight into the steps that are critical for the successful initiation of a TAVI program.

Reply

2012-04-01

We thank Dr. Cerillo and colleagues for their thoughtful and insightful comments on our paper (). In their letter, they have highlighted the benefit of using time series analysis to assess learning curve and quality control, and we generally agree with their comments. The traditional method of assessing surgical results is the retrospective analysis of outcome data as used in our study. Statistical testing in this regard is an appropriate way of assessing the learning curve when the interest is in determining whether or not a difference has reached a magnitude of statistical significance. However, when a plateau is reached, and/or formal testing is of less interest than detection, a time series analysis, and in particular the cumulative sum (CUSUM) analysis, may be a more appropriate tool for this analysis.

Chronic Total Occlusion: A Job for the “Heart Team”

Spencer B. King — 2012-04-01

I am often asked to speak about the development of percutaneous coronary interventions (PCIs) and where they are projected to go in the future. When the subject turns to the frontiers in coronary interventions, chronic total occlusion (CTO) always takes center stage. In this issue of JACC: Cardiovascular Interventions, there are 3 articles and 1 editorial dealing with issues related to CTO (). One is a group effort at proposing an algorithm for approaching CTO with the general concept of developing concentrated expertise in an organized approach to CTOs; another is a specialized technique for an antegrade approach to CTO intervention; and a third is reporting the survival benefit of successful CTO interventions compared to those that are unsuccessful. The editorial makes the case for attempting more CTOs and reflects on many observational studies that suggest improved survival with successful intervention on CTOs compared with unsuccessful intervention. We have recently published other papers aimed at improving our readership's prowess in dealing with CTOs. Several CTO clubs have sprung up in the United States, Japan, Europe, and other places because of the growing interest in this subset of coronary interventions. With so much interest, one wonders why such a small percentage of CTOs are undergoing attempted PCI. According to the latest guideline of the American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions, only 8% to 15% of patients with CTO undergo attempted PCI (). The reasons usually proposed for this are the technical difficulty and modest success rate of CTO interventions, and the uncertainty of the clinical benefit.