John A. Bittl

Myonecrosis After Revascularization Procedures

The detection of elevated cardiac enzyme levels and the occurrence of electrocardiographic (ECG) abnormalities after revascularization procedures have been the subject of recent controversy. This report represents an effort to achieve a consensus among a group of researchers with data on this subject. Creatine kinase (CK) or CK-MB isoenzyme (CK-MB) elevations occur in 5% to 30% of patients after a percutaneous intervention and commonly during coronary artery bypass graft surgery (CABG). Although Q wave formation is rare, other ECG changes are common. The rate of detection is highly dependent on the intensity of enzyme and ECG measurement. Because most events occur without the development of a Q wave, the ECG will not definitively diagnose them; even the ECG criteria for Q wave formation signifying an important clinical event have been variable. At least 10 studies evaluating > 10,000 patients undergoing percutaneous intervention have demonstrated that elevation of CK or CK-MB is associated not only with a higher mortality, but also with a higher risk of subsequent cardiac events and higher cost. Efforts to identify a specific cutoff value below which the prognosis is not impaired have not been successful. Rather, the risk of adverse outcomes increases with any elevation of CK or CK-MB and increases further in proportion to the level of intervention. This information complements similar previous data on CABG. Obtaining preprocedural and postprocedural ECGs and measurement of serial cardiac enzymes after revascularization are recommended. Patients with enzyme levels elevated more than threefold above the upper limit of normal or with ECG changes diagnostic for Q wave myocardial infarction (MI) should be treated as patients with an MI. Patients with more modest elevations should be observed carefully. Clinical trials should ensure systematic evaluation for myocardial necrosis, with attention paid to multivariable analysis of risk factors for poor long-term outcome, to determine the extent to which enzyme elevation is an independent risk factor after considering clinical history, coronary anatomy, left ventricular function and clinical evidence of ischemia. In addition, tracking of enzyme levels in clinical trials is needed to determine whether interventions that reduce periprocedural enzyme elevation also improve mortality.

Increased coronary perforation in the new device era: Incidence, classification, management, and outcome

BackgroundThe incidence of coronary perforation using new percutaneous revascularization techniques may be increased compared with PTCA. Still, perforation is uncommonly reported, and the optimal management and expected outcome remain unknown. The objectives of the study were to determine the incidence of coronary perforation using balloon angioplasty (percutaneous transluminal coronary angioplasty, PTCA) and new revascularization techniques and to develop optimal strategies for its management based on classification and outcome. Methods and ResultsEleven sites with frequent use of new revascularization devices and prospective coding of consecutive procedures for coronary perforation during 1990 to 1991 contributed to a perforation registry. Patients with perforation were matched by device with an equal-sized cohort without perforation. Data were collected centrally, and all procedural cineangiograms were reviewed at a core angiographic laboratory. A classification scheme based on angiographic appearance of the perforation (I, extraluminal crater without extravasation; II, pericardial or myocardial blushing; III, perforation ≥ 1-mm diameter with contrast streaming; and cavity spilling) was evaluated as a predictor of outcome and as a basis for management. Perforation was observed in 62 of 12900 procedures reported (0.5%; 95% confidence interval, 0.4% to 0.6%), more commonly with devices intended to remove or ablate tissue (atherectomy, laser) than with PTCA (1.3%, 0.9% to 1.6% versus 0.1%, 0.1% to 0.1%; P < .001). The perforation population was notable for its advanced age (67 ± 10 years) and high incidence of female sex (46%) (both P < .001 compared with patients without perforation). Perforation could be treated expectantly or with PTCA but without cardiac surgery in 85%, 90%, and 44% of class I, II, and III perforations, respectively. Class I perforations (n = 13, 21%) were associated with death in none, myocardial infarction in none, and tamponade in 8%. The incidences of these adverse events were 0%, 14%, and 13% in class II perforations (n = 31, 50%) and 19%, 50%, and 63% in non-cavity spilling class III perforations, respectively (n = 16, 26%). Two of the 15 instances of cardiac tamponade (13%) were delayed, occurring within 24 hours after dismissal from the catheterization laboratory. ConclusionThe incidence of perforation, while low, is increased with new devices. Women and the elderly are at highest risk. The clinical risk after perforation can be classified angiographically, but even low-risk perforations occasionally have poor clinical outcome. Patients should be observed for delayed cardiac tamponade for at least 24 hours.

Transcatheter umbrella closure of valvular and paravalvular leaks

OBJECTIVES Our aim was to adapt the technique of transcatheter umbrella closure of intracardiac defects for closure of valvular and paravalvular defects. BACKGROUND The double-umbrella device developed by Rashkind and Cuaso has been safely and effectively delivered across a host of intracardiac defects, but transcatheter closure of valvular and paravalvular leaks has not been reported. METHODS Between February 1987 and September 1990, eight patients who were believed to be poor operative candidates were taken to the catheterization laboratory for transcatheter double-umbrella closure of a valvular or a paravalvular leak. Four patients had a paravalvular leak around a prosthetic aortic valve. The other four patients had a valvular leak: one patient with a regurgitant native aortic valve after a Stansel procedure and three patients with a regurgitant porcine valve in a left ventricular apex to descending aorta conduit. RESULTS Placement of a double-umbrella device was attempted in seven of the eight patients and was successful in all seven. Device placement was not attempted in one patient because of the crescentic shape of his defect. Two patients required two devices for each closure; the other five required only one device each. Angiography, performed on six patients after device closure, demonstrated that three patients had a completely occluded defect, two had trivial residual flow and one patient had mild residual flow through the device. All significant complications occurred in one patient who had hemolysis and oliguria that resolved when the initial umbrella was replaced by a larger device. In addition, two devices migrated to the patients pulmonary arteries but were retrieved in the catheterization laboratory without difficulty. No other early or late complications occurred in 21 to 50 months of follow-up. Of the four patients with a paravalvular leak, the one who did not receive a device died at operation, one patient died at operation for an associated defect (in the operating room the umbrella was found securely in place across the paraaortic defect) and two patients are clinically well at home after 21 and 32 months, respectively. Of the four patients with closure of a valvular leak, one patient remains well at home 50 months later, one patient died at operation for associated defects and two patients had additional successful surgical treatment and remain well 29 months after device placement. CONCLUSIONS Transcatheter umbrella closure appears to be a reasonable alternative for closure of a valvular or paravalvular leak in patients who are poor operative candidates.

Coronary artery perforation during excimer laser coronary angioplasty

OBJECTIVES The aim of this study was to analyze the risk of vessel perforation during excimer laser angioplasty. BACKGROUND Vessel perforation is a serious complication of angioplasty. METHODS A total of 764 patients had 858 stenoses treated with excimer laser angioplasty. Laser catheters had a diameter of 1.4, 1.7 or 2 mm. Laser energy was delivered in pulses of 135 ns, at a frequency of 25 s-1 and at a fluence of 30 to 60 mJ/mm2. Follow-up angiography was requested for all patients who did not require emergency bypass surgery. RESULTS In the 764 consecutive patients treated with excimer laser coronary angioplasty, vessel perforation occurred in 23 patients (3%). Nine patients had a major complication resulting directly from vessel perforation (cardiac tamponade, myocardial infarction or need for bypass surgery) and 14 had no clinical complications after successful sealing of the puncture site. No patient with a perforation died. Multivariate analysis showed that bifurcation lesions (odds ratio [OR] = 3.5; p = 0.049), diabetes mellitus (OR = 3.15; p = 0.029) and female gender (OR = 2.86; p = 0.013) were associated with an increased risk of vessel perforation. Lesions > 10 mm in length (OR = 0.45; p = 0.206), calcified stenoses (OR = 0.26; p = 0.088) and saphenous vein graft lesions (OR = 0.50; p = 0.295) were not at increased risk. Vessel perforation was seen in 10 (8.3%) of 120 lesions in which the laser catheter was equivalent in diameter to the target vessel (< or = 0.5 mm smaller in size) but in only 8 (1.5%) of 525 lesions in which the laser catheter was > 1 mm smaller than the target vessel (p = 0.001). CONCLUSIONS Most lesions thought to be suitable for excimer laser treatment are not at increased risk of perforation. The complication may be avoided by improved patient and laser catheter size selection.

Complications and long-term outcome after percutaneous coronary angioplasty in chronic hemodialysis patients

The objective of this investigation was to assess the acute and long-term outcome after coronary angioplasty in patients undergoing chronic hemodialysis. Previous studies have suggested a high incidence of restenosis after coronary angioplasty performed in patients with renal failure. Medical discharge abstracts for 8342 patients undergoing angioplasty during a 5-year period were searched to identify all coronary angioplasty procedures performed in patients undergoing chronic hemodialysis. Procedural and follow-up coronary angiograms were reviewed in a core angiographic laboratory. Hospital records and office visit notes were obtained to assess acute and long-term outcome. Twenty-one patients undergoing chronic hemodialysis had been treated by coronary angioplasty. The 9 men and 12 women had a mean age of 59 +/- 10 years (range 37 to 78 years) and had been undergoing hemodialysis for 6.2 +/- 6.4 years (range 1 to 19 years). Procedural success was achieved in 12 (57%) of 21 patients. Three (14%) patients died; 4 suffered nonfatal myocardial infarctions (19%); 1 (5%) required emergency bypass surgery; and 1 (5%) had abrupt vessel closure without complications. Of the 15 (71%) patients who were discharged with a patent angioplasty vessel, 4 (27%) died and 9 (60%) had recurrence of angina within 1 year. Of 9 patients with recurrent angina, 7 underwent a second angiography, and all showed evidence of restenosis at the previous angioplasty site. The results of coronary angioplasty in these 21 hemodialysis patients suggest a high rate of acute complications and poor long-term prognosis in this subgroup. Other strategies for revascularization should be considered for these patients.

Excimer laser-facilitated coronary angioplasty. Relative risk analysis of acute and follow-up results in 200 patients.

BackgroundExcimer laser coronary angioplasty has been reported to be a promising treatment for complex coronary artery disease. The purpose of this study was to define the predictors of acute success and restenosis after this experimental intervention. Methods and ResulsA cohort of 200 consecutive patients had a minimum of 6 months of follow-up evaluation after treatment of 215 coronary stenoses that were carefully selected for excimer laser coronary angioplasty. At the time of the initial procedure, the laser catheter alone produced a residual stenosis of ≤50% at 119 of 215 lesions (55.4%). For complete dilatation, 87.9% of the lesions required adjunctive balloon angioplasty. Clinical success was achieved in 183 of the 200 patients (91.5%), as indicated by a reduction by at least 20% of the narrowing of the vessel diameter, ≤50% residual stenosis, and no in-hospital complication. Complications included abrupt closure (5.0%), myocardial infarction (3.5%), bypass surgery (3.0%), perforation (2.0%), and death (0.0%). Logistic regression analysis showed that lesions at vessel bifurcations (success rate, 66%; adjusted odds ratio [OR] = 0.16; p = 0.002) or in tortuous vessels (success rate, 82%; OR = 0.48; p = 0.004) were associated with decreased clinical success. However, acceptable success rates were achieved in patients with lesions in saphenous vein grafts more than 3 years old (success rate, 94%; OR = 1.40; p = 0.75), in ostial lesions (success rate, 100%; OR = 3.36; p = 0.43), and in lesions longer than 10 mm (success rate, 93.5%; OR = 1.50; p = 0.39). Clinical follow-up was available in 197 of the 200 patients (98.5%) a mean of 5.9±1.9 months after angioplasty, at which time 31.0% of patients had developed symptoms or evidence of ischemia. No patient died during the study. Follow-up angiography was obtained in 83.1% of eligible patients after a mean [±SD] of 5.2±2.0 months. Angiographic restenosis, defined by >50% stenosis, appeared at 78 of 164 lesions (47.6%). By logistic regression analysis, only lesions in saphenous vein grafts were associated with a decreased rate of restenosis (restenosis rate, 20%; OR = 0.18; p = 0.01). ConclusionsThis analysis, which defines the profile of risk for excimer laser angioplasty, provides a sound basis for rigorous comparison of adjunctive excimer laser with balloon angioplasty for ostial narrowings, long lesions, and saphenous vein graft stenoses.

Bivalirudin and Provisional Glycoprotein IIb/IIIa Blockade Compared With Heparin and Planned Glycoprotein IIb/IIIa Blockade During Percutaneous Coronary Intervention

A. Michael Lincoff, MD John A. Bittl, MD Robert A. Harrington, MD Frederick Feit, MD Neal S. Kleiman, MD J. Daniel Jackman, MD Ian J. Sarembock, MD David J. Cohen, MD Douglas Spriggs, MD Ramin Ebrahimi, MD Gadi Keren, MD Jeffrey Carr, MD Eric A. Cohen, MD Amadeo Betriu, MD Walter Desmet, MD Dean J. Kereiakes, MD Wolfgang Rutsch, MD Robert G. Wilcox, MD Pim J. de Feyter, MD Alec Vahanian, MD Eric J. Topol, MD for the REPLACE-2 Investigators

Contractile failure and high-energy phosphate turnover during hypoxia: 31P-NMR surface coil studies in living rat.

Cardiac failure appears rapidly during severe hypoxia and precedes a substantial reduction in adenosine triphosphate content. Reduced adenosine triphosphate turnover, in the presence of nearly normal content, may be the metabolic basis for contractile failure during hypoxia. To measure both the myocardial content and the turnover rates of high-energy phosphate compounds during hypoxia, we performed 31P-nuclear magnetic resonance studies by placing a surface coil directly over the left ventricle in intubated rats that were instrumented for hemodynamic measurements and ventilated with either 21, 10, or 8% O2. Normoxia produced a hemodynamic and metabolic steady state for 4 hours and hypoxia for at least 60 minutes. Under normoxic ventilation (n = 10, mean +/- SD), the arterial PO2 was 96 +/- 14, pH 7.38 +/- 0.11, and systolic blood pressure 96 +/- 8 mm Hg; under hypoxic ventilation with 10% O2 (n = 5), the arterial PO2 was 57 +/- 10, pH 7.39 +/- 0.09, and systolic pressure 68 +/- 10; and under hypoxic ventilation with 8% O2 (n = 5), the PO2 was 52 +/- 7, pH 7.37 +/- 0.04, and systolic pressure 51 +/- 4. Hypoxic ventilation with 10 or 8% O2 decreased the creatine phosphate content from 51.4 +/- 5.4 mumol/g dry wt to 39.3 +/- 5.4 and 45.6 +/- 4.1 and depressed adenosine triphosphate slightly from 25.0 mumol/g dry wt to 21.8 +/- 2.1 and 21.9 +/- 1.0, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute complications of excimer laser coronary angioplasty: A detailed analysis of multicenter results

OBJECTIVES The aim of this study was to document and analyze the incidence and consequences of complications of excimer laser coronary angioplasty. BACKGROUND Excimer laser coronary angioplasty has been reported to be a safe and feasible alternative or adjunct to conventional balloon angioplasty, but serious and unique complications have been observed. METHODS Data on 1,595 interventions of excimer laser coronary angioplasty in 1,521 patients were analyzed, using a merged data base from the U.S. and European Percutaneous Excimer Laser Coronary Angioplasty (PELCA) registries. RESULTS Procedural success was achieved in 89.3% of interventions. Stand-alone laser angioplasty was performed in 17.8% of interventions. Complications included dissection (22.0%), vasospasm (6.1%), filling defects (4.8%), abrupt reclosure (6.1%), embolization (2.3%), perforation (2.4%), arrhythmia (0.7%) and aneurysm formation (0.3%). Major complications were non-Q wave myocardial infarction (2.3%), Q wave myocardial infarction (1.0%), coronary artery bypass grafting (3.1%) and death (0.7%). Logistic regression analysis revealed correlation between dissections and the use of larger catheter size (p = 0.0005), high energy per pulse levels (p = 0.0001 for native vessels), lesion length > 10 mm (p = 0.001) and presence of a side branch (p = 0.01). The incidence of perforations was higher in women (p = 0.004), in treatment of total occlusions (p = 0.02) and in the presence of a side branch (p = 0.03). Fatal complications were correlated with patients with multivessel disease (p < 0.0001), patients with acute myocardial infarction (p = 0.0009) and older patients (> 70 years old, p = 0.004). The incidence of major complications decreased after performance of 50 laser angioplasty procedures at one institution (p = 0.02). CONCLUSIONS This analysis defines both the learning curve and the profile of complications for excimer laser angioplasty and provides insight into the selection of appropriate patients and proper performance of the procedure.

Relation between clinical presentation and angiographic findings in unstable angina pectoris, and comparison with that in stable angina

The diagnosis of unstable angina encompasses a broad spectrum of patients with myocardial ischemia, varying widely in cause, prognosis and responsiveness to therapy. A new clinical classification of unstable angina is based on the following 2 components: severity, and the clinical setting in which unstable angina develops. The hypothesis that this clinical classification correlates with the underlying coronary artery anatomy was tested. In 238 consecutive patients, an unstable angina score ranging from 2 to 6 was determined by adding the scores for severity (1 = unstable angina without pain at rest; 2 = pain at rest > 48 hours before angiography; and 3 = pain at rest < or = 48 hours before angiographic evaluation) and the clinical setting of unstable angina (1 = unstable angina secondary to a noncardiac condition; 2 = primary unstable angina; and 3 = early postinfarction unstable angina). Fifty concurrently studied consecutive patients with stable angina were assigned a score of 0. Patients with unstable angina averaged 63 +/- 11 years of age, and 165 were men (69%). Pain at rest occurred in 202 of 238 patients (85%), and angiography was performed < or = 48 hours in 139 of these patients (69%). Among patients with unstable angina, 5 (2%) had secondary unstable angina, 143 (60%) had primary unstable angina, and 90 (38%) had postinfarction unstable angina. Multivariable regression analysis identified the unstable angina score as the most important predictor of intracoronary thrombus (p = 0.011) and lesion complexity (p = 0.004) in the ischemia-related artery.(ABSTRACT TRUNCATED AT 250 WORDS)