Richard J. Katz

The effect of diabetes on outcomes of patients with advanced heart failure in the BEST trial

OBJECTIVES This was a retrospective analysis to determine the effect of diabetes on outcome in patients with advanced heart failure (HF), and to determine the effect of beta-blockade in patients with HF with and without diabetes mellitus. BACKGROUND In chronic HF the impact on clinical outcomes and therapeutic response of the prevalent comorbid condition diabetes mellitus has not been extensively investigated. METHODS We assessed the impact of diabetes on prognosis and effectiveness of beta-blocker therapy with bucindolol in patients with HF enrolled in the Beta-Blocker Evaluation of Survival Trial (BEST). We conducted a retrospective analysis to examine the prognosis of patients with advanced HF with and without diabetes, and the effect of beta-blocker therapy on mortality and HF progression or myocardial infarction (MI). The database was the 2,708 patients with advanced HF (36% with diabetes and 64% without diabetes) who were randomized to the beta-blocker bucindolol or placebo in BEST and followed for mortality, hospitalization, and MI for an average of two years. RESULTS Patients with diabetes had more severe chronic HF and more coronary risk factors than patients without diabetes. Diabetes was independently associated with increased mortality in patients with ischemic cardiomyopathy (adjusted hazard ratio 1.33, 95% confidence interval 1.12 to 1.58, p = 0.001), but not in those with a nonischemic etiology (adjusted hazard ratio 0.98, 95% confidence interval 0.74 to 1.30, p = 0.89). Compared with patients without diabetes, in diabetic patients beta-blocker therapy was at least as effective in reducing death or HF hospitalizations, total hospitalizations, HF hospitalizations, and MI. Ventricular function and physiologic responses to beta-blockade were similar in patients with and without diabetes. CONCLUSIONS Diabetes worsens prognosis in patients with advanced HF, but this worsening appears to be limited to patients with ischemic cardiomyopathy. In advanced HF beta-blockade is effective in reducing major clinical end points in patients with and without diabetes.

A randomized, angiographically controlled trial of intracoronary streptokinase in acute myocardial infarction

Fifty-five patients with acute myocardial infarction evaluated within 4 hours of the onset of symptoms were entered into an angiographically controlled trial of intracoronary streptokinase (IC STK). Forty-three patients with total occlusion of their infarct artery were randomized to either IC STK or intracoronary nitroglycerin (IC NTG), and 12 patients with less-than-complete occlusion received only IC NTG. Reperfusion of a totally occluded vessel was achieved in 69% of STK patients and 17% of IC NTG patients. Time from onset of symptoms to peak CK activity was significantly shorter in reperfused patients and patients with subtotal occlusion on initial angiography than in patients with total occlusion who were not reperfused (p less than 0.0001). Comparison of radionuclide ejection fractions (EF) determined acutely and 10 to 14 days after infarction failed to show improvement in either the STK or IC NTG group (mean decrease of 2.8% and 0.4%, respectively). In contrast, patients with subtotal occlusion on baseline angiography demonstrated a significant (p = 0.05) spontaneous improvement in EF over 2 weeks (7.3% increase).

Definition of the best prediction criteria of the time domain signal-averaged electrocardiogram for serious arryhthmic events in the postinfarction period

Objective. The goal of this study was to establish guidelines for the prognostic use of the time domain signal-averaged electrocardiogram (ECG) after myocardial infarction. Background. Previous studies of the prognostic use of the signal-averaged ECG in postinfarction patients had one or more of the following limitations: a small study group, empiric definition of an abnormal recording and possible bias in the selection of high risk groups or classification of arrhythmic events, or both. To correct for these limitations, a substudy was conducted in conjunction with the Cardiac Arrhythmia Suppression Trial (CAST). Methods. Ten centers recruited 1,211 patients with acute myocardial infarction without application of the ejection fraction or Holter criteria restrictions of the main CAST protocol. Several clinical variables, ventricular arrhythmias on the Holter recording, ejection fraction and six signal-averaged ECG variables were analyzed. Patients with bundle branch block were exluded from the analysis, and the remaining 1,158 were followed for up to 1 year after infarction. The classification of arrhythmic events was reviewed independently by the CAST Events Committee. Results. During an average (±SD) follow-up of 10.3 ± 3.2 months, 45 patients had a serious arrhythmic event (nonfatal ventricular tachycardia or sudden cardiac arrhythmic death). A Cox regression analysis with only the six signal-averaged ECG variables indicated that the filtered QRS duration at 40 Hz ≥120 ms (QRSD-40 Hz) at a cutpoint ≥120 ms was the most predictive criterion of arrhythmic events. In a regression analysis that included all clinical, Holter and ejection fraction variables, a QRSD-40 Hz ≥120 ms was the most significant predictor (p Conclusions. The signal-averaged ECG predicts serious arrhythmic events in the first year after infarction better than do clinical, ejection fraction and ventricular arrhythmia variables, and QRSD-40 Hz ≥120 ms provides the best predictive criterion in this clinical setting.

Prevention of nitrate tolerance with angiotension converting enzyme inhibitors.

BackgroundActivation of neurohumoral hormones or sulflhydryl group depletion may contribute to the development of nitroglycerin tolerance. In an attempt to prevent nitrate tolerance, this study evaluated the interaction of nitroglycerin with angiotensin converting enzyme (ACE) inhibitors with and without a sulfhydryl group. Methods and ResultsThirty-four subjects were randomized to a 7-day regimen of enalapril 10 mg b.i.d., captopril 25 mg t.i.d., or placebo. Venodilator response to nitroglycerin was assessed with forearm plethysmography by measuring the change in venous volume after administration of 0.4 mg sublingual nitroglycerin. Plethysmographic measurements were obtained serially 1) at baseline, 2) after 4 days of ACE inhibitor or placebo, 3) 2 hours after application of a 10 mg/24 hr nitroglycerin patch, and 4) 74 hours after continuous nitropatch application. ACE inhibition alone caused no significant change in the response to sublingual nitroglycerin. Nitrate response remained unchanged after 2 hours (“acute”) of nitropatch exposure in all three groups. After 74 hours (“chronic”) of continuous nitropatch application, the venodilator response to sublingual nitroglycerin was reduced by 40% in the placebo group, 10% in the enalapril group, and 2% in the captopril group. This attenuation was significant only in the placebo group (p < 0.01). Pairwise comparison of nitrate response between groups was significantly different between the captopril and placebo groups (p < 0.01) and between the placebo and enalapril groups (p < 0.05). Plasma renin levels increased equally in the enalapril and captopril groups. Body weight increased only in the placebo group, suggesting prevention of nitrate-induced volume expansion in the ACE inhibitor groups. ConclusionsThis study demonstrates that ACE inhibitors may prevent nitrate tolerance to long-term nitrate therapy.

The Cardiac Arrhythmia Suppression Trial: first CAST ... then CAST-II.

The Cardiac Arrhythmia Suppression Trial (CAST) was a study designed to test the hypothesis that suppression of ventricular premature complexes after a myocardial infarction would improve survival. Preliminary results showed that suppression of ventricular premature complexes with encainide and flecainide worsened survival, and the CAST continued as the CAST-II with moricizine compared with its placebo. The protocol for the CAST-II was changed to attempt to enroll patients more likely to experience serious arrhythmias. The enrollment time was narrowed to 4 to 90 days after myocardial infarction; the qualifying ejection fraction was lowered to less than or equal to 0.40; a higher dose of moricizine could be used; early titration itself was double-blind with a placebo, and the definition of disqualifying ventricular tachycardia was changed to allow patients with more serious arrhythmias to be entered into the trial. The Cardiac Arrhythmia Suppression Trial-II was subsequently terminated prematurely because 1) patients treated with moricizine had an excessive cardiac mortality rate during the 1st 2 weeks of exposure to the drug, and 2) there appeared to be little chance of showing a long-term survival benefit from treatment with moricizine. This report outlines the rationale behind the Cardiac Arrhythmia Suppression Trial and the reasons for selection of the drugs used in the CAST and CAST-II.

Treatment of frequent ventricular arrhythmia with encainide: assessment using serial ambulatory electrocardiograms, intracardiac electrophysiologic studies, treadmill exercise tests, and radionuclide cineangiographic studies.

The effects of encainide on ventricular arrhythmia and left ventricular function were studied in 21 patients with chronic, high-grade ventricular arrhythmia using a prospective, 3-month, placebo-controlled, single-blind trial design. Encainide caused a 96% decrease in the average hourly frequency of ventricular premature complexes (VPCs) and comparable reductions in salvos of nonsustained ventricular tachycardia (VT) and episodes of sustained VT. Intracardiac electrophysiologic testing showed prolonged intraatrial and intraventricular conduction times and increased atrial, atrioventricular nodal, and ventricular refractory periods with both i.v. and oral encainide without His-Purkinje block, despite marked prolongation of HV and QRS intervals. Induced repetitive ventricular beating after ventricular extrastimuli in 15 patients showed persistent repetitive ventricular beating with chronic oral encainide in seven patients, four of whom had sustained VT within 2 months of treatment on encainide. Encainide did not reduce exercise capacity or left ventricular ejection fraction at rest or during supine exercise. Minor adverse effects of encainide in 11 of 21 patients included dose-related visual disturbances, dizziness and sinus pauses (< 3 seconds). Major adverse effects included the new appearance of sustained VT in three of 20 patients (15%). Oral encainide effectively reduces the frequency and grade of VPCs, prolongs intracardiac conduction times, and does not impair left ventricular performance. However, it is associated with frequent minor side effects and uncommon but potentially severe major side effects (sustained VT), both of which apparently have a direct relationship to the size of the dose.

Association of Serum Antibodies to Heat-Shock Protein 65 With Coronary Calcification Levels. Suggestion of Pathogen-Triggered Autoimmunity in Early Atherosclerosis

Background—Previous studies demonstrated an association between antibodies to mycobacterial heat-shock protein 65 (mHSP65) and carotid artery thickening. We examined whether mHSP65 antibodies are associated with levels of coronary calcification that appear to reflect preclinical coronary artery disease (CAD). Methods and Results—Serum specimens from 201 healthy asymptomatic subjects (52% male; mean age, 56.6 years) undergoing electron-beam computed tomographic imaging were used to measure levels of mHSP65 and human HSP60 antibodies and antibodies to several infectious pathogens. We found that 84% of the study subjects had anti-mHSP65 IgG antibodies. Mean titers of mHSP65 antibodies were higher (1:394 versus 1:267, P =0.012) in individuals with than in those without elevated levels of coronary calcium (calcium score ≥150). Increasing titers of mHSP65 antibodies were significantly associated, in a dose-response manner, with elevated levels of coronary calcification. Individuals with the highest titers of mHSP65 antibodies (≥1:800) had an adjusted odds ratio (OR) of 14.3 for having elevated coronary calcium (P =0.004). Association of mHSP65 antibodies with elevated coronary calcification levels was independent of CAD risk factors after multivariate adjustment (P =0.037). Interestingly, mHSP65 antibody titers were correlated with Helicobacter pylori infection (P =0.004), which maintained significance after adjustment for CAD risk factors and seropositivities to other pathogens (adjusted OR, 3.1; 95% CI, 1.4 to 6.6). No association was found between antibodies to human HSP60 and levels of coronary calcification. Conclusions—Antibodies to mHSP65 are associated with elevated levels of coronary calcification and correlated with H pylori infection, suggesting that pathogen-triggered autoimmunity plays a role in early atherosclerosis.

Myocardial metabolic and hemodynamic effects of dobutamine in heart failure complicating coronary artery disease.

Eighteen patients with congestive heart failure (CHF) complicating coronary artery disease (CAD) and seven patients with CHF due to primary cardiomyopathy (CM) were studied during infusions of dobutamine in doses of 2.5–15.0 μg/kg/min. There were statistically significant (p < 0.05) improvements in cardiac index, stroke volume index, left ventricular stroke work index and nuclear ejection fraction in both groups. Significant decreases (p < 0.05) in pulmonary capillary wedge pressure, right atrial pressure, and systemic and pulmonary vascular resistances were also observed in both groups. However, five patients increased an already elevated pulmonary capillary wedge pressure during dobutamine infusion, which was associated with either the development of angina pectoris or with a significant elevation of the mean arterial pressure. In the CAD patients, gated cardiac scans analyzed for segmental wall motion showed improvement in 27% of the abnormally contracting segments during dobutamine infusion. Finally, the effects of dobutamine on myocardial metabolism were assessed with arterial and coronary sinus lactate analysis. Fourteen of the 18 CAD patients (78%) showed no metabolic abnormality during dobutamine infusion; four CAD patients (22%), three of whom developed typical angina pectoris, displayed abnormal lactate metabolism. None of the CM patients developed angina pectoris or displayed abnormal lactate metabolism. Of the seven patients with an adverse hemodynamic or metabolic response, four had recently been withdrawn from propranolol therapy. In conclusion, dobutamine produced favorable effects on hemodynamics, left ventricular ejection fraction, and segmental wall motion abnormalities in most patients with CHF without a deleterious effect on myocardial metabolism.

Efficacy of oral diltiazem to control ventricular response in chronic atrial fibrillation at rest and during exercise

Although digoxin is often the first choice for control of ventricular response in chronic atrial fibrillation, it fails to slow exercise rates. Diltiazem, a calcium channel antagonist that slows atrioventricular conduction, was administered to 16 patients who failed to achieve adequate rate control on low level exercise testing despite digoxin therapy. Therapeutic response to diltiazem was assessed with submaximal and maximal exercise tests and 24 hour ambulatory electrocardiographic monitoring. During the diltiazem treatment phase, ventricular response at rest diminished (96 +/- 17 versus 69 +/- 10 beats/min, p less than 0.001) as did rate during submaximal exercise (155 +/- 28 versus 116 +/- 26, p less than 0.001), maximal exercise (163 +/- 14 versus 133 +/- 26, p less than 0.001) and average ventricular response during 24 hour monitoring (87 +/- 13 versus 69 +/- 10, p less than 0.001). Rate at rest decreased 26 +/- 15% and submaximal exercise rate diminished 24 +/- 12%. Thirteen (81%) of the 16 patients exhibited at least 15% slowing of rate at rest and during submaximal exercise. Eleven patients (69%) reported alleviation of symptoms. There was no change in serum digoxin levels during diltiazem treatment (1.3 +/- 0.5 versus 1.3 +/- 0.6 ng/ml, p = NS). On withdrawal of diltiazem, ventricular response returned to baseline values. Diltiazem is an effective agent for control of ventricular response, both at rest and during exercise, in digoxin-treated patients with chronic atrial fibrillation.

Sustained antianginal efficacy of transdermal nitroglycerin patches using an overnight 10-hour nitrate-free interval

The antianginal efficacy of the transdermal nitroglycerin patch may be limited by the rapid development of tolerance during uninterrupted exposure. To address this problem, we investigated the role of intermittent therapy was investigated, using a daily nitroglycerin patch-free interval in 13 patients with chronic stable angina. Concomitant antianginal medications were permitted. Entry criteria required reproducible exercise times to both onset of angina and 1 mm of ST-segment depression. In each patient the highest tolerated nitroglycerin patch dose was determined by a dose-titration phase, which was then used in a double-blind crossover trial comprising 2 randomized treatment arms: 1 week of active nitroglycerin patch and 1 week of matching placebo. All patches were worn only from 8 A.M. to 10 P.M. daily. Exercise testing was repeated before patch application and then 4 and 8 hours after application on both the first and the last day of each treatment arm. Eleven patients completed the randomized crossover phase. Exercise time to the onset of angina and to the onset of 1 mm of ST-segment depression was significantly prolonged during the first day of therapy at both 4 and 8 hours after active nitroglycerin patch application compared with placebo (p less than 0.01). During sustained use, the benefit at 4 and 8 hours after nitroglycerin patch application was still evident (p less than 0.001 and p less than 0.05, respectively). No evidence of a overnight rebound or withdrawal phenomenon was observed by history or by ambulatory Holter monitoring calibrated for ST-segment analysis.(ABSTRACT TRUNCATED AT 250 WORDS)