4329Mega-studies in heart failure, effect dilution in examination of new therapies

Aims

All phase 3 studies in patients with acute heart failure (AHF) and HF with preserved ejection fraction (HFpEF) have failed in the last decades. We explore the likelihood that the negative results are due to chance and/or to study size and dilution of statistical power.

Methods and results

First, using simulations, we examined the probability that a positive finding in phase 2 would result in studying truly effective drugs in phase 3. We simulated phase 2 studies under six scenarios where the range of true relative risk (RR) for an outcome of interest varied from 0.5 (major benefit) to 1.15 (some harm). The proportion of simulated studies where the RR <0.8 (we assumed that a 20% or greater risk reduction reflects an effective drug) ranged from 6% to 42% across the six scenarios studied. To further simulate “real life” clinical research, we simulated a continuous surrogate outcome that was linearly related to the true RR in each simulation of each scenario. Regardless of criteria considered for a positive phase 2 trial, results suggest that even in our worst-case scenario, where overall only 6% of drugs taken into phase 2 are effective, roughly 20% of phase 3 studies, if appropriately powered, should have yielded positive results. Given this, we then explored study size in AHF research, as a potential explanation for the high failure rate in these studies. Comparison of published phase 2 and 3 clinical trials with registries in AHF suggest that populations in both large and small trials differ from “real life”. Meta-regression models suggest that both control event rates, and in the serelaxin program as an example, treatment effects, decline with increasing study size greatly reducing power (figure). This effect dilution might be explained by an increasing proportion of patients enrolled in studies who cannot benefit from the study drug.

Figure 1. Power at two-sided 0.05 significance level to detect an effect size of hazard ratio of 0.65 (left) or 0.8 (right) with a placebo event rate of 10% (top) and 20% (bottom) at N=100 at various treatment effect dilutions with increasing sample size.

Conclusion

These data suggest that it is unlikely that the very high rate of negative AHF phase III trials can be explained by chance alone. Potentially, our tendency to increase sample size does not necessarily increase statistical power, due to more heterogenous populations leading to reduced event rates and treatment effects.

Acute hemodynamic and clinical effects of levosimendan in patients with severe heart failure. Study Investigators

BACKGROUND

We determined the short-term hemodynamic and clinical effects of levosimendan, a novel calcium-sensitizing agent, in patients with decompensated heart failure.

METHODS AND RESULTS

One hundred forty-six patients with New York Heart Association functional class III or IV heart failure (mean left ventricular ejection fraction 21+/-1%) who had a pulmonary capillary wedge pressure >/=15 mm Hg and a cardiac index </=2.5 L x min(-1) x m(-2) were enrolled in a multicenter, double-blind, placebo-controlled study and randomized 2:1 to intravenous infusion of levosimendan or placebo. Drug infusions were uptitrated over 4 hours from an initial infusion rate of 0.1 microg x kg(-1) x min(-1) to a maximum rate of 0.4 microg x kg(-1) x min(-1) and maintained at the maximal tolerated infusion rate for an additional 2 hours. Levosimendan caused dose-dependent increases in stroke volume and cardiac index beginning with the lowest infusion rate and achieving maximal increases in stroke volume and cardiac index of 28% and 39%, respectively. Heart rate increased modestly (8%) at the maximal infusion rate and was not increased at the 2 lowest infusion rates. Levosimendan caused dose-dependent decreases in pulmonary capillary wedge, right atrial, pulmonary arterial, and mean arterial pressures. Levosimendan appeared to improve dyspnea and fatigue, as assessed by the patient and physician, and was not associated with a significant increase in adverse events.

CONCLUSIONS

Levosimendan caused rapid dose-dependent improvement in hemodynamic function in patients with decompensated heart failure. These hemodynamic effects appeared to be accompanied by symptom improvement and were not associated with a significant increase in the number of adverse events. Levosimendan may be of value in the short-term management of patients with decompensated heart failure.

Echocardiographic predictors of clinical outcome in patients with left ventricular dysfunction enrolled in the SOLVD registry and trials: significance of left ventricular hypertrophy. Studies of Left Ventricular Dysfunction

OBJECTIVES

To assess the relation of left ventricular (LV) and left atrial (LA) dimensions, ejection fraction (EF) and LV mass to subsequent clinical outcome of patients with LV dysfunction enrolled in the Studies of Left Ventricular Dysfunction (SOLVD) Registry and Trials.

BACKGROUND

Data are lacking on the relation of LV mass to prognosis in patients with LV dysfunction and on the interaction of LV mass with other measurements of LV size and function as they relate to clinical outcome.

METHODS

A cohort of 1,172 patients enrolled in the SOLVD Trials (n = 577) and Registry (n = 595) had baseline echocardiographic measurements and follow-up for 1 year.

RESULTS

After adjusting for age, New York Heart Association (NYHA) functional class, Trial vs. Registry and ischemic etiology, a 1-SD difference in EF was inversely associated with an increased risk of death (risk ratio, 1.62; p = 0.0008) and cardiovascular (CV) hospitalization (risk ratio, 1.59; p = 0.0001). Consequently, the other echo parameters were adjusted for EF in addition to age, NYHA functional class, Trial vs. Registry and ischemic etiology. A 1-SD difference in LV mass was associated with increased risk of death (risk ratio of 1.3, p = 0.012) and CV hospitalization (risk ratio of 1.17, p = 0.018). Similar results were observed with the LA dimension (mortality risk ratio, 1.32; p < 0.02; CV hospitalizations risk ratio, 1.18; p < 0.04). Likewise, LV mass > or =298 g and LA dimension > or =4.17 cm were associated with increased risk of death and CV hospitalization. An end-systolic dimension >5.0 cm was associated with increased mortality only. A protective effect of EF was noted in patients with LV mass > or =298 g (those in the group with EF >35% had lower mortality) but not in the group with LV mass <298 g.

CONCLUSIONS

In patients with LV dysfunction enrolled in the SOLVD Registry and Trials, increasing levels of hypertrophy are associated with adverse events. A protective effect of EF was noted in patients with LV mass > or =298 g (those in the group with EF >35% fared better) but not in the group with LV mass <298 g. These data support the development and use of drugs that can inhibit hypertrophy or alter its characteristics.

Reproducibility of impedance cardiography hemodynamic measures in clinically stable heart failure patients

BACKGROUND AND AIMS. One of the greatest challenges confronting physicians who are managing the care of patients with heart failure is to acquire objective data that signals treatment effectiveness and/or disease progression. The aim of this study was twofold: 1) to determine the extent to which (real time) impedance cardiography measurements obtained with a specific medical device (the BioZ) were reproducible in outpatients with clinically stable heart failure; and 2) to establish "normal" ranges of one week hemodynamic variability in this population of patients. Information of this nature would help clinical cardiologists and primary care practitioners to evaluate the implications of their patient's visit-to-visit hemodynamic variability. METHODS. A one group, prospective, time series design was used. The sample consisted of 62 patients who had clinically stable heart failure and who were being treated in an outpatient heart failure clinic at a university medical center. BioZ hemodynamic measures of cardiac output, contractility, and after load were obtained at five points in time: two, 10, and 60 minutes resting following a 40-50 foot walk on the first day and at two and 10 minutes resting following a 40-50 foot walk on the second day, one week later. RESULTS. Small but significant changes in cardiac output and cardiac index (mainly due to changes in heart rate) were seen during the 60-minute period on week one. Stroke index did not change during this period. In general, reproducibility between measurements taken on the same day and between days was quite good. Establishment of 95% confidence intervals helped define boundaries of variability in this population. Further clinical evaluation of the four patients whose values exceeded the 95% confidence intervals revealed unexpected, potentially relevant changes that could have accounted for their interday variability. Conclusion. The BioZ impedance cardiography measurements are responsive to hemodynamic activity-rest changes and are reproducible at a one week interval in clinically stable heart failure patients being treated in an outpatient clinic. Stroke index is a better measure of patient status than cardiac output or cardiac index. (c)2000 by CHF, Inc.

Tumor necrosis factor-alpha upregulates angiotensin II type 1 receptors on cardiac fibroblasts

Angiotensin II (Ang II) plays an important role in post-myocardial infarction (MI) remodeling. Most Ang II effects related to remodeling involve activation of the type 1 receptor (AT(1)). Although the AT(1) receptor is upregulated on cardiac fibroblasts post-MI, little is known about the mechanisms involved in the process. Consequently, we tested whether growth factors known to be present in the remodeling heart increased AT(1) mRNA levels. Using quantitative competitive reverse transcription-polymerase chain reaction, we found that norepinephrine, endothelin, atrial natriuretic peptide, and bradykinin had no significant effect on AT(1) mRNA levels. Ang II, transforming growth factor-beta(1), and basic fibroblast growth factor reduced AT(1) mRNA levels (P<0.02). Tumor necrosis factor-alpha (TNF-alpha), however, produced a marked increase in AT(1) mRNA. After 24 hours of TNF-alpha incubation, AT(1) mRNA increased by 5-fold above control levels (P<0.01). The EC(50) for the TNF-alpha effect was 4.6 ng/mL (0.2 nmol/L). Interleukin (IL)-1beta caused a 2.4-fold increase, whereas IL-2 and IL-6 had no significant effect. Studies of TNF-alpha enhancement of AT(1) mRNA levels demonstrate that the increase was not due to a change in transcript stability. TNF-alpha treatment for 48 hours also resulted in a 3-fold increase in AT(1) surface receptor and a 2-fold increase in Ang II-induced production of inositol phosphates. The present findings provide evidence for TNF-alpha regulation of AT(1) receptor density on cardiac fibroblasts. Because TNF-alpha concentration and AT(1) receptor density increase in the myocardium after MI, these results raise the possibility that TNF-alpha modulates post-MI remodeling by enhancing Ang II effects on cardiac fibroblasts.

Angiotensin type 1 receptor antagonism with irbesartan inhibits ventricular hypertrophy and improves diastolic function in the remodeling post-myocardial infarction ventricle

To evaluate the role of angiotensin II (AII) on diastolic function during post-myocardial infarction (MI) ventricular remodeling, coronary ligation or sham operation was performed in male Sprague-Dawley rats. Experimental animals were maintained on either irbesartan, a selective AT1-receptor antagonist, or no treatment. Measurement of cardiac hypertrophy, diastolic function, and sarcoendoplasmic reticulum adenosine triphosphatase (ATPase; SERCA) and phospholamban (PLB) gene expression was assessed at 6 weeks after MI. Myocardial infarction caused a significant increase in myocardial mass and left ventricular (LV) filling pressure, whereas LV systolic pressure and +dP/dt were reduced. The time constant of isovolumic relaxation (tau) was markedly prolonged after MI. Post-MI hypertrophy was associated with substantial increases in the messenger RNA (mRNA) expression of atrial natriuretic peptide (ANP), but no significant changes in SERCA or PLB levels. Although irbesartan treatment did not significantly alter post-MI LV systolic or filling pressures, it nevertheless effectively decreased ventricular hypertrophy, improved tau, and normalized ANP expression. These results demonstrate that AT1-receptor antagonism has important effects on myocardial hypertrophy and ANP gene expression, which are independent of ventricular loading conditions. In addition, the improvement in diastolic function was not related to changes in SERCA and PLB gene expression, suggesting that enhanced myocardial relaxation was related to the blockade of AII effects on myocyte function or through a reduction of ventricular hypertrophy itself or both.

A dose-dependent increase in mortality with vesnarinone among patients with severe heart failure. Vesnarinone Trial Investigators

BACKGROUND

Vesnarinone, an inotropic drug, was shown in a short-term placebo-controlled trial to improve survival markedly in patients with severe heart failure when given at a dose of 60 mg per day, but there was a trend toward an adverse effect on survival when the dose was 120 mg per day. In a longer-term study, we evaluated the effects of daily doses of 60 mg or 30 mg of vesnarinone, as compared with placebo, on mortality and morbidity.

METHODS

We enrolled 3833 patients who had symptoms of New York Heart Association class III or IV heart failure and a left ventricular ejection fraction of 30 percent or less despite optimal treatment. The mean follow-up was 286 days.

RESULTS

There were significantly fewer deaths in the placebo group (242 deaths, or 18.9 percent) than in the 60-mg vesnarinone group (292 deaths, or 22.9 percent) and longer survival (P=0.02). The increase in mortality with vesnarinone was attributed to an increase in sudden death, presumed to be due to arrhythmia. The quality of life had improved significantly more in the 60-mg vesnarinone group than in the placebo group at 8 weeks (P<0.001) and 16 weeks (P=0.003) after randomization. Trends in mortality and in measures of the quality of life in the 30-mg vesnarinone group were similar to those in the 60-mg group but not significantly different from those in the placebo group. Agranulocytosis occurred in 1.2 percent of the patients given 60 mg of vesnarinone per day and 0.2 percent of those given 30 mg of vesnarinone.

CONCLUSIONS

Vesnarinone is associated with a dose-dependent increase in mortality among patients with severe heart failure, an increase that is probably related to an increase in deaths due to arrhythmia. A short-term benefit in terms of the quality of life raises issues about the appropriate therapeutic goal in treating heart failure.

Does the magnitude of mitral regurgitation determine hemodynamic response to vasodilation in chronic congestive heart failure?

Although it is usually assumed that direct-acting vasodilators improve cardiac function in patients with congestive heart failure (CHF) by altering left ventricular preload and afterload, several studies have suggested that most of the benefit occurs as a result of a reduction in associated mitral regurgitation (MR), which is present in the majority of patients with severe CHF. To test his hypothesis, the hemodynamic response to oral hydralazine was examined in CHF patients with competent mitral prostheses (group 1) and patients with CHF due to severe MR and left ventricular dysfunction (group 2). Both groups demonstrated significant increases in cardiac, stroke volume, and stroke work indices, although these were greater in group 2. Only group 2 experienced a significant reduction in left ventricular filling pressure. Thus, the presence of MR is not essential for hemodynamic improvement but is associated with significantly greater responses.

Medical therapy for patients with aortic insufficiency

The medical course and management of patients with aortic insufficiency depends on the severity of the valve lesion and acuity with which it develops. In this article a description of the basic pathophysiology of aortic insufficiency and the natural history of the disease is outlined. Recent information describing both the acute and long-term effects of vasodilator therapy is summarized. With this information, a rational approach to the medical management of aortic insufficiency is developed.

Medical management of congestive heart failure

The syndrome of congestive heart failure can result from a variety of cardiac disorders of which left ventricular dysfunction is the most common. The clinical presentation is determined by the interaction between cardiac dysfunction and a series of compensatory mechanisms that are activated throughout the body. Therapy for this disorder is best approached through an understanding of this complex relationship and an appreciation for the influence of preload, afterload, and contractility on cardiac performance. Recent important advances in therapy include the use of combined diuretic therapy, a better understanding of the value of the digitalis glycosides, and evidence that angiotensin-converting enzyme (ACE) inhibitors can relieve symptoms and prolong life. More intensive therapy earlier in the course of congestive heart failure appears to have some clinical benefit. The use of ACE inhibitors during this phase may delay progression of the underlying left ventricular dysfunction. Future therapy will be influenced by the results of ongoing trials that are testing both new agents and expanded indications for drugs that are currently available.

Vasodilatory effects of lidocaine on epicardial porcine coronary arteries

To investigate the mechanism of lidocaine's effect to cause vasorelaxation, swine epicardial mid-right coronary arterial rings were placed under constant (5 g) tension in a muscle bath, precontracted with 35 mmol/l KCl and exposed to increasing concentrations of lidocaine (3-2,000 micrograms/ml). At a concentration of 10 micrograms/ml, mild vasoconstriction occurred, increasing tension 1.9 +/- 0.1% above baseline. Vasodilation began to occur at 30 micrograms/ml and was maximal at 2,000 micrograms/ml, reducing tension 97.5 +/- 0.2% below baseline. Vasodilation was not altered significantly by removal of endothelium or by pretreatment with propranolol or indometacin.

Left ventricular response to submaximal and maximal exercise in asymptomatic aortic regurgitation

In patients with chronic aortic regurgitation the quantitative changes in loading conditions and left ventricular performance from rest to submaximal exercise have not been related to the magnitude of change observed from rest to maximal exercise. Changes in end-diastolic volume index, as a measure of preload, and measures of contractile performance (ejection fraction and the systolic blood pressure/end-systolic volume index ratio) were assessed at rest, submaximal and maximal supine bicycle exercise using radionuclide angiography in 74 patients with chronic moderate to severe aortic regurgitation. With exercise, end-diastolic volume index decreased in a stepwise manner from 166 +/- 47 to 152 +/- 41 to 143 +/- 41 ml/m2 at rest, submaximal and maximal exercise, respectively. For the entire group, these changes were not associated with a significant change in ejection fraction but were associated with stepwise increases in systolic blood pressure to end-systolic volume index ratio. However, when patients were divided into 3 subgroups based on an increase (group I), minimal change (group II) or a decrease (group III) in ejection fraction from rest to maximal exercise, stepwise increases in systolic blood pressure to end-systolic volume index were again observed in groups I and II but not in group III. These changes were significantly greater in group I than in group II at submaximal and maximal exercise levels. Differences in ejection fraction response and end-diastolic and end-systolic volumes with exercise in the 3 groups were evident at the submaximal exercise level.(ABSTRACT TRUNCATED AT 250 WORDS)

Beneficial effects of the calcium antagonist PN 200-110 in patients with congestive heart failure

We studied the acute hemodynamic effects of PN 200-110, a newly available calcium antagonist, in 12 patients with severe congestive heart failure. Measurements of cardiac performance were obtained by a right heart catheter before and after administration of 5 and 15 mg of PN. Peak drug effects occurred 1-2 h following the administration of PN 200-110 and were dose related. The 15-mg dose reduced mean arterial pressure (MAP) from 90 +/- 11 to 75 +/- 6 mm Hg (mean +/- SD) (p less than 0.001) and decreased systemic vascular resistance (SVR) from 1,740 +/- 500 to 995 +/- 300 dynes X s X cm-5 (p less than 0.01). Stroke volume index (SVI) increased from 26 +/- 7 to 36 +/- 10 ml/m2 (p less than 0.001), and cardiac index (CI) rose from 2.1 +/- .3 to 2.8 +/- .6 L/m2 (p less than 0.01). Pulmonary arterial wedge pressure (PAW) changed insignificantly. Seven patients performed graded supine exercise at identical workloads before and after treatment. When peak exercise values were compared, the addition of PN 200-110 further reduced SVR from 1,282 +/- 461 to 936 +/- 356 dynes X s X cm-5 (p less than 0.01) and increased CI from 3.3 +/- 1.1 to 4.3 +/- 1.3 L/m2 (p less than 0.01). Only minor, self-limiting side effects were noticed during acute administration. Of the seven patients discharged on PN 200-110 and followed for at least 6 months, six reported substantial relief of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Static exercise with congestive heart failure and the response to vasodilating drugs

The hemodynamic response to static exercise in 28 patients with congestive heart failure (CHF) was compared with that in 8 control subjects. Static handgrip exercise at 50% of the maximal voluntary contraction was performed to fatigue. In patients with CHF, pulmonary arterial wedge pressure increased from 20 +/- 18 to 31 +/- 10 mm Hg (p less than 0.001) (mean +/- standard deviation) and systemic vascular resistance increased from 1,730 +/- 454 to 2,151 +/- 724 dynes s cm-5 (p less than 0.001). Although cardiac index did not change significantly, stroke volume index and stroke work index decreased from 24 +/- 6 to 20 +/- 6 ml/m2 (p less than 0.001) and 28 +/- 11 to 25 +/- 12 g-m/s2 (p less than 0.05), respectively. In control subjects, pulmonary arterial wedge pressure did not change significantly; cardiac index increased from 3.6 +/- 0.3 to 4.0 +/- 0.4 liters/min/m2 (p less than 0.05) and systemic vascular resistance increased slightly, from 1,011 +/- 186 to 1,106 +/- 180 dynes s cm-5 (p less than 0.05). The effects of arterial dilation with hydralazine on the response to static exercise were assessed in 10 of the patients with CHF. Compared with predrug exercise, cardiac index increased 68% (p less than 0.01), stroke volume index increased 76% (p less than 0.01) and systemic vascular resistance decreased 47% (p less than 0.01) after administration of hydralazine. Thus, static exercise can have adverse effects on cardiac performance in patients with CHF.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between functional class and cardiac performance in patients with chronic aortic insufficiency

We have evaluated the relationship of New York Heart Association functional class (FC) assessment to rest and exercise hemodynamics and resting left ventricular (LV) functional data in 75 consecutive patients with isolated, chronic aortic insufficiency. Although there was a tendency for hemodynamic and angiographic variables to worsen as FC increased there was considerable overlap between patients assigned to the various groups. Statistically significant differences were seen only for resting left ventricular end-diastolic pressure (LVEDP) and pulmonary artery wedge (PAW) pressure which were higher in FC 3/4 patients than in FC 1 or 2 patients. The results of our study suggest that FC assignment cannot be used to accurately define underlying LV performance or hemodynamics in an individual patient with chronic aortic insufficiency. However, since severe abnormalities are unlikely to be present in asymptomatic patients, routine detailed frequent investigation does not seem warranted in this group. As FC worsens, the likelihood of left ventricular dysfunction increases. Thus, the presence of symptoms is an indication for more extensive evaluation.

Ejection fraction response to supine exercise in asymptomatic aortic regurgitation: relation to simultaneous hemodynamic measurements

The change in ejection fraction during exercise is frequently employed as a measure of left ventricular functional reserve in patients with aortic regurgitation. However, little information is available about its relation to invasive measurements of cardiac performance. Therefore, simultaneous hemodynamic measurements and supine exercise blood pool scintigraphy were performed in 14 patients with severe, asymptomatic or minimally symptomatic aortic regurgitation associated with cardiomegaly but preserved left ventricular function at rest. Their hemodynamic measurements at rest were normal and their exercise capacity was excellent. When the patients were categorized into those patients whose ejection fraction increased or did not decrease by more than 0.05 (Group 1) and those whose ejection fraction decreased by more than 0.05 (Group 2), important differences were apparent. Echocardiographic, radionuclide and hemodynamic measurements at rest in the two patient groups were similar, but Group 1 exhibited a greater increase in cardiac index during supine exercise (2.8 +/- 0.4 to 10.0 +/- 1.8 versus 2.7 +/- 0.5 to 6.9 +/- 1.0 liters/min per m2; p less than 0.005) and a lesser increase in pulmonary capillary wedge pressure (13 +/- 4 to 19 +/- 7 versus 12 +/- 4 to 31 +/- 8 mm Hg; p less than 0.01). The severity of regurgitation decreased during exercise in all patients, but end-diastolic volume decreased and end-systolic volume decreased or was unchanged in Group 1, whereas end-diastolic volume was unchanged and end-systolic volume increased in Group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

The preoperative evaluation in patients with endocarditis. Is cardiac catheterization necessary?

We retrospectively compared clinical assessment and cardiac catheterization to subsequent surgical findings with regard to specific valvular involvement, hemodynamic status, and presence of myocardial abscess in patients recommended for cardiac surgery for endocarditis. Of 105 consecutive patients with endocarditis, 19 met one or more of the following criteria suggesting the need for early surgery: congestive heart failure; systemic emboli; persistent infections or new conduction abnormalities. Of these 19 patients, seven had prosthetic cardiac valves. Clinical assessment was highly sensitive (95 percent) and specific (89 percent) for specific valvular involvement and was also highly sensitive and specific in evaluating myocardial abscess and congestive heart failure; however, clinical assessment could not identify the source of infection in one patient with multiple prosthetic valves, did not define the specific valve in one patient with right-sided endocarditis, and overestimated the severity of mitral regurgitation in one patient who had normal pressures and flows at catheterization. Catheterization incorrectly predicted multivalvular involvement in four patients. At catheterization, only one patient experienced evidence of clinical deterioration, and this was probably not related to the procedure. We conclude that although clinical assessment is correct in most patients, it may on occasion lead to an erroneous conclusion. Catheterization and angiograms are of value in the preoperative evaluation of patients with endocarditis, particularly in cases where the clinical assessment is ambiguous or uncertain. The procedures can be performed at low risk, and the information obtained may substantially influence management in some cases.

Acute effects of alcohol in patients with congestive heart failure

We evaluated the acute effects of moderate alcohol consumption in eight patients with New York Heart Association Functional Class III-IV congestive heart failure. Hemodynamic and echocardiographic variables were measured at baseline and then repeated at 30-minute intervals after ingestion of alcohol, 0.9 g/kg body weight, in the form of 80 proof vodka. Mean peak blood alcohol levels (+/- SE) at 60 minutes were 117 +/- 8 mg/dL. A significant reduction in mean arterial pressure, pulmonary artery and pulmonary artery wedge pressures, and systemic vascular resistance occurred over the first 90 minutes. Neither cardiac index, stroke volume index, stroke work index, nor echocardiographic variables were significantly changed. In patients with heart failure, a single moderate dose of alcohol reduces afterload by dilating arterial resistance vessels. No evidence of acute deterioration in cardiac performance was seen. In such patients occasional consumption of moderate dose alcohol can be safely tolerated.

Results of long-term vasodilator therapy in patients with refractory congestive heart failure

The long-term effects of vasodilator therapy with oral hydralazine and long-acting nitrates were studied in 34 patients with refractory heart failure. Seven patients who had marginal hemodynamic improvement despite optimal hydralazine therapy were not maintained on vasodilators, and eight who had a favorable hemodynamic response subsequently discontinued hydralazine therapy because of side effects. Of these 15 patients, four (27%) died and 11 remained in New York Heart Association functional class II or IV at a mean follow-up of 10 +/- 2 months (SEM). The 19 patients who received chronic therapy for 8 +/- 2 months were divided into nine late responders (47%), who improved to functional class I or II, and 10 late nonresponders (53%), who remained in functional class III or IV. Only one of the nine late responders (11%) died, compared with seven of the 10 late nonresponders (70%) (p less than 0.01). The actuarially determined survival at 1 year was 100% for late responders and 13 +/- 12% for late nonresponders (p less than 0.01). No clinical variable could distinguish late responders from late nonresponders. Hemodynamic variables measured before vasodilator therapy showed that late responders had a lower mean right atrial pressure (8 +/- 1 vs 17 +/- 3 mm Hg, p less than 0.01) and lower mean pulmonary artery wedge pressure (20 +/- 2 vs 30 +/- 2 mm Hg, p less than 0.005), higher stroke, volume index (27 +/- 2 vs 20 +/- 1 ml/m2, p less than 0.005) and higher stroke work index (32 +/- 4 vs 19 +/- 2 g-m/m2, p less than 0.01) than late nonresponders. There were no significant differences in the acute response to vasodilators between the two groups. We conclude that (1) a substantial portion of patients with refractory congestive heart failure either do not have a beneficial response to vasodilator therapy or discontinue it because of side effects; (2) about half of the patients who are maintained on chronic vasodilator therapy (or about one-fourth of the patients in whom therapy is initiated) had sustained clinical benefit; and (3) the initial hemodynamics, but not the clinical variables, are predictive of late mortality and late clinical response. Patients with evidence of more severe left ventricular dysfunction have an unfavorable course.

Mechanism for improved cardiac performance with arteriolar dilators in aortic insufficiency

To determine how arteriolar dilation improves cardiac performance in aortic insufficiency, we evaluated the acute effects of hydralazine in 10 patients with chronic severe aortic insufficiency. Control measurements of intracardiac and intravascular pressures, cardiac output and left ventricular volumes were obtained at cardiac catheterization. Hydralazine, 0.3 mg/kg i.v. (maximal dose 20 mg), was administered and all measurements were repeated 30 minutes later. A reduction in systemic vascular resistance from 1264 to 710 dyn-sec-cm-5 was associated with significant increases in forward cardiac index (2.9 to 5.1 l/min/m2) and stroke volume index (37 to 55 ml/m2). Left ventricular end-diastolic pressure was reduced from 19 to 12 mm Hg. There was a significant reduction in mean arterial pressure (88 to 83 mm Hg) and a significant increase in heart rate (81 to 94 beats/min). Regurgitant stroke volume was reduced by more than 10 ml/m2 in seven patients and for the group was significantly reduced, from 65 to 53 ml/m2. Regurgitant fraction was reduced in all patients; the overall reduction from 0.64 to 0.48 was highly significant. Ejection fraction increased more than 0.10 in four patients, by 0.08 in an additional patient and for the group increased significantly from 0.50 to 0.57. Left ventricular end-diastolic volume decreased by more than 25 ml/m2 in four patients, by 19 ml/m2 in an additional patient and was decreased significantly, from 208 to 190 ml/m2, for the group. Arteriolar dilators improve cardiac performance in aortic insufficiency by reducing the amount of aortic regurgitation and, in some patients, by substantially improving systolic pump fraction. These data suggest a role for arteriolar dilators in the management of selected patients with aortic insufficiency.

Long-term vasodilator therapy in aortic insufficiency. Evidence for regression of left ventricular dilatation and hypertrophy and improvement in systolic pump function

Although the beneficial effects of acute therapy with arteriolar dilators in aortic insufficiency have been shown, the results of long-term therapy are uncertain. The administration of oral hydralazine, 125 mg twice a day, to a 54-year-old woman with chronic severe aortic insufficiency resulted in sustained relief of heart failure symptoms. Repeat catheterization after 14 months showed hemodynamic improvement, substantial reduction in left ventricular chamber size and muscle mass, and recovery of systolic pump function. Chronic therapy with arteriolar dilators may be a useful alternative to valve replacement in selected patients with aortic insufficiency.

Beneficial effects of hydralazine on rest and exercise hemodynamics in patients with chronic severe aortic insufficiency

We studied the effects of afterload reduction in chronic severe aortic insufficiency by measuring the hemodynamic response to oral hydralazine in 10 consecutive patients. Hemodynamics were also measured during maximal exercise in eight of these patients. At rest, hydralazine reduced pulmonary artery wedge pressure from 14 to 9 mm Hg (p less than 0.01), and increased cardiac index by 70% and stroke volume index by 35% (both p less than 0.001). Before hydralazine, pulmonary artery wedge pressure exceeded 20 mm Hg in five patients during maximal exercise; with hydralazine, at identical levels of exercise, pulmonary artery wedge pressure remained below 20 mm Hg in all patients. For the group, hydralazine reduced pulmonary artery wedge pressure from 21 to 12 mm Hg (p less than 0.05) and increased cardiac index by 31% (p less than 0.05) during exercise; changes in stroke volume index were more variable and there was no significant increase for the group, although several patients increased stroke volume substantially and the overall increase was 34%. These data show that afterload reduction has beneficial effects on cardiac performance in chronic severe aortic insufficiency both at rest and during exercise. Hydralazine may be of use in such patients either in preparation for valve replacement or as interim therapy.

Evaluation of left ventricular performance by gated radionuclide angiography

Gated radionuclide angiography (RVG) in orthogonal projections was used to evaluate left ventricular volume, ejection fraction, and segmental wall motion. Images of the left ventricle at end-diastole and end-systole were outlined in two projections using a simple manual method. The perimeter drawings were digitized on a desktop computer, interfaced to an XY recorder and left ventricular volumes and ejection fraction calculated. The results were compared to contrast left ventriculography (CVG) in the same projections. RVG and CVG gave similar results for end-diastolic volume (r = .87, P less than 0.001), end-systolic volume (r = .95, P less than 0.001), and ejection fraction (r = .89, P less than 0.001) over a wide range of values. In 92% of all left ventricular segments analyzed, RVG and CVG showed only minor differences in the analysis of wall motion. Reproducibility of the method by a trained observer was excellent. Interobserver trials demonstrated that less well-trained observers consistently over- or underestimated volumes, emphasizing the need for prior experience in RVG analysis. Use of this manual method for analysis of gated equilibrium RVG in orthogonal projections appears to be a reasonably accurate, reproducible method for evaluating left ventricular function.

Thallium-201 myocardial perfusion scintigraphy to evaluate patients after coronary bypass surgery

To determine the utility of thallium-201 stress scintigraphy in assessing the results of coronary bypass surgery, chest pain, stress electrocardiograms and scintigrams were evaluated in 27 patients postoperatively. These findings were compared with coronary angiographic data in which a significant postoperative lesion was defined as 75 percent or more stenosis in a graft, its distal vessel or in an ungrafted native vessel. As an indicator of postoperative coronary lesions, chest pain lacked sensitivity (60 percent) and was nonspecific (20 percent). The stress electrocardiogram had poor sensitivity (60 percent) and good specificity (86 percent) but was not helpful in six patients who had equivocal or suboptimal tests. The scintigram had good sensitivity (77 percent) and was highly specific for the diagnosis of coronary stenosis. It was significantly more specific than chest pain (P less than 0.01), gave excellent localizing information and added to the accuracy of both conclusive and inconclusive stress tests. In nine patients with preoperative stress scintigrams, comparison of pre- and postoperative studies reflected the éffects of bypass surgery on coronary perfusion. Scintigraphy is a useful technique for the noninvasive evaluation of the patient after coronary bypass surgery, and postoperative scintigraphy alone is of great value in documenting surgical results.

Beneficial effects of hydralazine in severe mitral regurgitation

The severity of mitral regurgitation is, in part, determined by aortic impedance to left ventricular outflow. Sodium nitroprusside acutely decreases regurgitant flow, but the importance of its dual vasodilating effects, the lowering of peripheral vascular resistance and increasing of venous capacitance, is unclear. We studied the hemodynamic response to intravenous hydralazine, which selectively acts on the arteriolar resistance bed, in 10 patients with severe mitral regurgitation. Hydralazine produced a 50% increase in forward stroke volume (22 +/- 2 to 33 +/- 3 ml/m2, P less than 0.001) and a 33% reduction in regurgitant stroke volume (40 +/- 6 to 27 +/- 6 ml/m2, P less than 0.001), with a resultant fall in pulmonary capillary wedge v wave and mean pressures. Unlike nitroprusside, it did not alter left ventricular end-diastolic volume or pressure. Oral hydralazine maintained this hemodynamic improvement for at least 48 hours and, in three patients, provided more sustained clinical improvement. We conclude that hydralazine, by virtue of its selective lowering of aortic impedance, reduces the amount of mitral regurgitation and thus may be a useful mode of interim or chronic therapy in selected patients.

Primary type V hyperlipoproteinemia. A descriptive study in 32 families

We have studied 32 kindreds identified by propositi with primary type V hyperlipoproteinemia. The clinical presentation, metabolic associations, and natural history confirm the distinctiveness of primary type V hyperlipoproteinemia from other lipoprotein abnormalities. Although the underlying defect(s) remains unknown, several factors such as obesity, alcohol, drugs, and diet are able to modify the glyceridemia, the major manifestation of this disorder. Abnormalities of postheparin lipolytic activity or its subfractions do not appear to be involved in the pathogenesis of primary type V. The prevalence of hyperuricemia, diabetes, pancreatitis, and xanthomatosis appears high among the 32 propositi; the last two entities are much less prevalent in the relatives, even among those relatives classified as hyperglyceridemic. There is no evidence in these families of excessive coronary artery disease prevalence. Triglyceride levels are positively associated with age in this population, especially among women. Average triglyceride levels were lower for women than for men before age 50.

Ventricular septal defect and ventricular aneurysm secondary to acute myocardial infarction. Report of four cases with successful surgical treatment

Four cases of ventricular septal defect and ventricular aneurysm after myocardial infarction are reported. The clinical findings and surgical results in these four cases and in eight previously reported patients with this combination of complications are summarized. Resection of the ventricular aneurysm and closure of the ventricular septal defect appear indicated, both on theoretical grounds and in view of the excellent results observed in six patients who underwent combined repair. In one of our patients, closure of the ventricular septal defect and resection of the ventricular aneurysm were possible with only a single suture line, as these defects were anatomically contiguous.