Does the AHA/ACC task force grading system predict outcome in multivessel coronary angioplasty?

To assess the ACC/AHA task force grading system as a predictor of outcome in patients undergoing multivessel percutaneous transluminal coronary angioplasty we analyzed all failures (residual stenosis > 50%, Q-wave myocardial infarction, coronary artery bypass grafting during hospitalization, or death) in 97 patients with 328 stenoses. There were 70 males and 27 females; 60 patients had stable angina, and 37 had unstable angina. The mean number of lesions dilated per patient was 3.4 (range 2-8). The mean preangioplasty percent luminal diameter narrowing was 80 +/- 14%. Thirty-eight stenoses were AHA/ACC classification type A, 192 type B, and 98 type C. One hundred twenty-eight lesions were located in the left anterior descending artery or its distribution, 89 in the left circumflex, 96 in the right coronary artery, and 15 in other vessels. Procedural success (< 50% residual diameter narrowing and no major ischemic complications) was achieved in 266 lesions (81.1%). Major ischemic complications (death, myocardial infarction, or emergency bypass surgery) occurred in 8 patients (8.2%) and in-hospital mortality was 2%. Analysis on a per stenosis basis demonstrated 84% success in type A, 89% in type B, and 64% in type C (p < 0.0001). When type B was divided into type B1 (1 type B characteristic) and type B2 (two or more type B characteristics) the success rate was 90% vs. 88% and the complication rate was 1% vs. 2%, respectively (p = n.s.). Logistic regression analysis showed that the best single predictor of failed angioplasty was total occlusion > 3 months, followed by total occlusion < 3 months and severely angulated (> 90 degrees) segment.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term therapy with benazepril in patients with congestive heart failure: effects on clinical status and exercise tolerance

Benazepril hydrochloride (CGS 14824A) is an orally active, nonsulfhydryl compound that is transformed in vivo to a long-acting inhibitor of angiotensin-converting enzyme (ACE). Previous studies have shown benazepril to lower blood pressure in hypertensive patients and to confer acute hemodynamic benefits in patients with congestive heart failure (CHF). In the current multicenter investigation, 16 patients with chronic CHF due to left ventricular systolic dysfunction (ejection fraction less than 0.40 at rest) whose symptoms corresponded to New York Heart Association classes II to IV were given open-label benazepril once daily in ascending doses of 2 to 20 mg and followed biweekly for 12 weeks. Evaluation of the 15 subjects who completed the trial showed a progressive increase in treadmill exercise duration (from 7.65 +/- 3.64 [SD] minutes at baseline to 9.74 +/- 3.66 minutes at 12 weeks, P less than .001); augmentation of the mean left ventricular ejection fraction (from 0.266 +/- 0.133 at baseline to 0.292 +/- 0.136 at 12 weeks, P less than .025); relief of exertional dyspnea in 7 of the 15 patients (P less than .02); and improvement in global symptomatic status in 10 of the patients (P less than .01). These responses were accompanied by a reduction in serum ACE activity of 75% (from 27.2 +/- 10.5 IU/L at baseline to 6.7 +/- 1.9 IU/L at 12 weeks, P less than .001), which was independent of dose and duration of treatment. The magnitude of ACE inhibition did not correlate with changes in the efficacy variables. Aside from two instances of symptomatic hypotension (one of which was complicated by volume depletion), the drug was well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics of N-acetylprocainamide in patients profiled with a stable isotope method

N-Acetylprocainamide (NAPA) absorption and disposition were profiled in five patients with ventricular arrhythmias by the simultaneous intravenous administration of NAPA-13C and oral administration of a 500 mg NAPA hydrochloride tablet. NAPA distribution was modeled with a three compartment mammillary system. The central compartment volume of 14.1 +/- 2.6 L (mean +/- SD) was similar to expected intravascular space, corrected for NAPA partitioning between erythrocytes and plasma. Other compartment volumes, intercompartmental and nonrenal clearances, and the steady-state distribution volume of 1.45 +/- 0.09 L/kg were similar to normal subject values. The least-squares estimate of 1.67 for the NAPA renal clearance/creatinine clearance ratio was similar to the value of 1.68 previously reported for functionally anephric patients and showed the expected age-associated decrease. The oral NAPA dose was 78.0% +/- 11.7% absorbed and interindividual variation in NAPA absorption was correlated with fast intercompartmental clearance (r = 0.89, p = 0.045). Because fast intercompartmental clearance partly reflects splanchnic blood flow, hemodynamic changes may affect NAPA bioavailability, as has been found for procainamide.

Low heart rate variability and sudden cardiac death

Our results indicate the following. 1. HRV is markedly depressed in inducible SCD survivors, a group at high risk of a subsequent episode of SCD. 2. Studies on patients who developed SCD during Holter monitoring indicate that HRV is depressed prior to SCD. 3. HRV is markedly depressed in inducible "asymptomatic ventricular ectopy" patients, with the degree of reduction paralleling that observed in inducible SCD survivors. In contrast, HRV of noninducible "asymptomatic ventricular ectopy" patients did not differ statistically from normal. 4. The findings provide additional evidence that cardiac parasympathetic function is depressed in patients prone to development of SCD and that altered autonomic function contributes to the development of electrical instability in such individuals. This accords with findings that such risk factors for sudden death as coronary artery disease, myocardial infarction, congestive failure, and hypertension all have been associated with reduced parasympathetic activity or attenuation of parasympathetically mediated reflexes. It is tempting to believe that diminished cardiac parasympathetic activity, perhaps by failing to counter excess sympathetic activity, contributes to SCD. 5. It may be inferred that HRV measurements have potential for serving as an independent predictor of inducibility in response to programmed ventricular stimulation and that they could represent a noninvasive screen for patients referred for evaluation of risk of SCD because of asymptomatic ventricular ectopy or other causes. In a larger sense, the data suggest that HRV measurements may provide information pertinent to the identification of individuals at increased risk of SCD that is independent of that provided by other risk factors. Given the human and economic stakes, further study is clearly warranted.

Acute effects of digoxin on total systemic vascular resistance in congestive heart failure due to dilated cardiomyopathy: a hemodynamic-hormonal study

The effects of the digitalis glycosides on systemic vascular resistance (SVR) in patients with congestive heart failure (CHF) are controversial. Most investigators report a reduction in total SVR, an action that has been attributed primarily to withdrawal of elevated sympathetic tone. Direct proof of this hypothesis is lacking, however, and the roles played by the renin-angiotensin-aldosterone and vasopressin systems have not been fully explored. Moreover, in several studies of patients with CHF, SVR did not decrease after the administration of digitalis. To clarify these issues, the hemodynamic and hormonal effects of digoxin were correlated in 11 normotensive men in sinus rhythm with CHF due to dilated cardiomyopathy. Patients were evaluated at rest and during submaximal exercise before and 6 hours after the intravenous infusion of 1.0 mg of digoxin (mean serum concentration 1.7 ng/ml). With digoxin therapy, heart rate, pulmonary wedge pressure and right atrial pressure declined and cardiac output increased. Although vasopressin was unchanged, both plasma norepinephrine concentrations and plasma renin activity decreased, the reduction in norepinephrine correlating with the increase in cardiac output. Despite these hemodynamic and hormonal effects, there was no change in total SVR at rest or during exercise. It is concluded that the improvement in cardiac function with digoxin in this patient group was a result of the inotropic properties of the drug, without an associated reduction in impedance. The failure of total SVR to decrease despite decreases in plasma norepinephrine levels and plasma renin activity might be explained by concomitant digitalis-induced vasoconstriction, impaired ability of arterioles to dilate in CHF, or offsetting alterations in other vasoactive hormone systems.