Metoprolol in dilated cardiomyopathy: is it possible to identify factors predictive of improvement? The Heart Muscle Disease Study Group

How can optimization of medical treatment avoid unnecessary implantable cardioverter-defibrillator implantations in patients with idiopathic dilated cardiomyopathy presenting with "SCD-HeFT criteria?"

To assess the proportion and long-term outcomes of patients with idiopathic dilated cardiomyopathy and potential indications for implantable cardioverter-defibrillator before and after optimization of medical treatment, 503 consecutive patients with idiopathic dilated cardiomyopathy were evaluated from 1988 to 2006. A total of 245 patients (49%) satisfied the "Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) criteria," defined as a left ventricular ejection fraction of ≤0.35 and New York Heart Association (NYHA) class II-III on registration. Among these, 162 (group A) were re-evaluated 5.4 ± 2 months later with concurrent β-blockers and angiotensin-converting enzyme inhibitor use. Of the 162 patients, 50 (31%) still had "SCD-HeFT criteria" (group A1), 109 (67%) had an improved left ventricular ejection fraction and/or New York Heart Association class (group A2), and 3 (2%) were in NYHA class IV. Of the 227 patients without baseline "SCD-HeFT criteria" (left ventricular ejection fraction >0.35 or NYHA class I), 125 were evaluated after 5.5 ± 2 months. Of these 227 patients, 13 (10%) developed "SCD-HeFT criteria" (group B1), 111 (89%) remained without "SCD-HeFT criteria" (group B2), and 1 (1%) had worsened to NYHA class IV. The 10-year mortality/heart transplantation and sudden death/sustained ventricular arrhythmia rate was 57% and 37% in group A1, 23% and 20% in group A2 (p <0.001 for mortality/heart transplantation and p = 0.014 for sudden death/sustained ventricular arrhythmia vs group A1), 45% and 41% in group B1 (p = NS vs group A1), 16% and 14% in group B2 (p = NS vs group A2), respectively. In conclusion, two thirds of patients with idiopathic dilated cardiomyopathy and "SCD-HeFT criteria" at presentation did not maintain implantable cardioverter-defibrillator indications 3 to 9 months later with optimal medical therapy. Their long-term outcome was excellent, similar to that observed for patients who had never met the "SCD-HeFT criteria."

Are nonsustained ventricular tachycardias predictive of major arrhythmias in patients with dilated cardiomyopathy on optimal medical treatment?

BACKGROUND

To evaluate the role of nonsustained ventricular tachycardias (NSVT) for the prediction of major ventricular arrhythmias (MVA) in patients with idiopathic dilated cardiomyopathy (DCM) after optimization of medical treatment.

METHODS AND RESULTS

Three hundred nineteen consecutive DCM patients were evaluated after adequate stabilization on optimal angiotensin-converting enzyme (ACE) inhibitor (88%) and beta-blocker (82%) therapy. Frequency, length, and rate of NSVT at 24-hour Holter monitoring were analyzed to assess their values in predicting MVA (unexpected sudden death, SVT, ventricular fibrillation, and appropriate implantable cardioverter defibrillator interventions). During follow-up (median 96 months, 1(st)-3(rd) interquartile range 52-130), MVA incidence was low, and not statistically different between patients with and without NSVT (3 and 2 per 100 patient-years, respectively, P = nonsignificant [NS] at log-rank analysis). At multivariable analysis, the number of NSVT was predictive of MVA only if left ventricular ejection fraction (LVEF) was > 0.35 (two NSVT/day vs no NSVT/day: hazard ratio [HR] 5.3, 95% confidence interval [CI] 1.59-17.85 in LVEF > 0.35 vs HR 0.93, 95% CI 0.3-2.81 in LVEF < or = 0.35). Consequently, in patients with LVEF < or = 0.35, MVA incidence rates were similar regardless of NSVT (3.6 and 4.1 patient-years, respectively, in those with and without NSVT, P = NS), while in patients with LVEF > 0.35, MVA incidence (3.1 per 100 patient-years vs 0.9 per 100 patient-years, P = 0.003) was significantly higher when NSVT were present.

CONCLUSIONS

After medical stabilization, NSVT did not increase the risk of MVA in patients with DCM and LVEF < or = 0.35. Conversely, the number and length of NSVT runs were significantly related to the occurrence of MVA in the patients with LVEF > 0.35.

Improvement of cardiac function persists long term with medical therapy for left ventricular systolic dysfunction

In certain patients with left ventricular (LV) systolic dysfunction, improvements in cardiac function are seen after initiation of medical therapy; however, the long-term stability of ventricular function in such patients is not well described. We retrospectively analyzed 171 patients who had a baseline ejection fraction of 45% or less, a follow-up echocardiogram at 2 to 12 months after initiation of medical therapy, and a final echocardiogram. We found that 48.5% of the patients demonstrated initial improvements in LV function after initiation of medical therapy, and the improvements appear to be sustained (88% of patients) at 44 +/- 21 months follow-up. A nonischemic etiology and younger age were the only independent predictors of change of LV ejection fraction of 10 or more at a mean 8.4 +/- 3.4 months after optimal medical therapy. Our study revealed a trend toward improved long-term survival in individuals with an early improvement in LV ejection fraction with medical therapy, especially in those with sustained improvement.

Influence of heart rate, blood pressure, and beta-blocker dose on outcome and the differences in outcome between carvedilol and metoprolol tartrate in patients with chronic heart failure: results from the COMET trial

AIMS

We studied the influence of heart rate (HR), systolic blood pressure (SBP), and beta-blocker dose on outcome in the 2599 out of 3029 patients in Carvedilol Or Metoprolol European Trial (COMET) who were alive and on study drug at 4 months after randomization (time of first visit on maintenance therapy).

METHODS AND RESULTS

By multivariable analysis, baseline HR, baseline SBP, and their change after 4 months were not independently related to subsequent outcome. In a multivariable analysis including clinical variables, HR above and SBP below the median value achieved at 4 months predicted subsequent increased mortality [relative risk (RR) for HR>68 b.p.m. 1.333; 95% confidence intervals (CI) 1.152-1.542; P<0.0001 and RR for SBP>120 mmHg 0.78; 95% CI 0.671-0.907; P<0.0013]. Achieving target beta-blocker dose was associated with a better outcome (RR 0.779; 95% CI 0.662-0.916; P<0.0025). The superiority of carvedilol as compared to metoprolol tartrate was maintained in a multivariable model (RR 0.767; 95% CI 0.663-0.887; P=0.0004) and there was no interaction with HR, SBP, or beta-blocker dose.

CONCLUSION

Beta-blocker dose, HR, and SBP achieved during beta-blocker therapy have independent prognostic value in heart failure. None of these factors influenced the beneficial effects of carvedilol when compared with metoprolol tartrate at the pre-defined target doses used in COMET.

Pacing techniques in heart failure: current concepts and future outlook

In addition to the well established benefits of traditional pacing methods, newer, left ventricular-based pacing techniques appear to induce significant hemodynamic improvements, benefit cardiac remodeling, improve functional capacity, and may decrease hospitalizations in appropriately selected patients with advanced systolic heart failure and intraventricular conduction defects. Encouraging results have been suggested from preliminary observational studies as well as from controlled clinical trials. Despite the generally positive outlook, much remains to be learned about multisite pacing techniques, appropriate site and patient selection, and long-term effectiveness.

Relation between heart rate, heart rhythm, and reverse left ventricular remodelling in response to carvedilol in patients with chronic heart failure: a single centre, observational study

OBJECTIVE

To determine whether the process of reverse left ventricular remodelling in response to carvedilol is dependent on baseline heart rate (BHR), heart rhythm, or heart rate reduction (HRR) in response to carvedilol.

DESIGN

Retrospective analysis of serial echocardiograms in 257 patients with chronic systolic heart failure at baseline and at 12-18 months after starting carvedilol. Reverse left ventricular remodelling was determined by changes in left ventricular end diastolic dimension (LVEDD), end systolic dimension (LVESD), and fractional shortening (LVFS).

SETTING

Heart failure clinic within a university teaching hospital.

MAIN OUTCOME MEASURES

Changes in LVEDD, LVESD, and LVFS.

RESULTS

LVEDD and LVESD decreased by 2.6 (0.4) mm and 4.9 (0.5) mm, respectively (mean (SEM)), and LVFS increased by 4.3 (0.5)% (all p < 0.0001 v baseline). Simple regression revealed no significant relation between BHR or HRR and the changes in LVEDD, LVESD, or LVFS. Stratification of patients into high and low BHR groups (above and below the mean) or according to the baseline heart rhythm (sinus rhythm v atrial fibrillation) showed no differences between groups in the extent of reverse left ventricular remodelling. Improvements in left ventricular function and dimensions were associated with significant improvements in New York Heart Association functional class.

CONCLUSIONS

The benefits of carvedilol in terms of reverse left ventricular remodelling and symptomatic improvement in patients with chronic heart failure are independent of BHR, heart rhythm, and the HRR that occurs in response to carvedilol.

Marked improvement in left ventricular ejection fraction during long-term beta-blockade in patients with chronic heart failure: clinical correlates and prognostic significance

BACKGROUND

Some patients with heart failure (HF) may have a marked improvement in left ventricular ejection fraction (LVEF) after long-term beta-blockade. We compared the clinical characteristics and the prognosis of these patients with those of other patients.

METHODS

One hundred seventy-one patients with chronic HF were assessed before and after 9 to 12 months of maintenance therapy with metoprolol or carvedilol.

RESULTS

Thirty-eight patients (22%) showed an increase in their LVEF >or=15 units (from 20% +/- 8% to 43% +/- 10%). Compared with the other patients (LVEF change from 21% +/- 7% to 26% +/- 9%, P <.0001 for differences between groups), these patients also had a greater decline in the left ventricular end-diastolic volume (from 175 +/- 74 mL/m(2) to 113 +/- 36 mL/m(2)) and in the right atrial, mean pulmonary artery, and pulmonary wedge pressures, with a greater increase in the cardiac index, stroke volume index, stroke work index, and maximal functional capacity. Their long-term prognosis was excellent, with a 2-year cumulative survival rate of 95%, versus 81% for the other patients, and a hospitalization-free survival rate of 73%, versus 50% for the other patients (all P <.05). By means of multivariate analysis, only the nonischemic cause of HF and the mean arterial pressure at baseline were independently associated with an increase of >or=0.15 in LVEF.

CONCLUSIONS

Patients who show a marked improvement in their LVEF after long-term beta-blockade have an excellent prognosis and have a high prevalence of nonischemic HF and a higher blood pressure at baseline.

Dobutamine echocardiography in idiopathic dilated cardiomyopathy: clinical and prognostic implications

The dobutamine echocardiographic test (DET) is frequently used in coronary artery disease to detect viable myocardium, but few data are available about its role in idiopathic dilated cardiomyopathy (IDCM). The aims of this study were to evaluate the clinical role of DET and the prognostic implications of the 'contractile reserve' in patients with IDCM treated with optimal medical therapy, including beta-blockade (BB). A total of 51 patients with IDCM underwent DET at diagnosis. A positive response to DET (DET+) was judged to be a significant increase (> or =10 points) in left ventricular ejection fraction (LVEF) with a peak value > or =40%, and a reversed restrictive left ventricular filling pattern (RFP) if present at baseline study. Improvement at follow-up was defined according to combined clinical and echo-Doppler criteria. In all, 22 patients (43%) were classified as DET+. DET+ patients were less symptomatic (P<0.001), with lower heart rate (P<0.01), less enlarged left and right ventricles (P<0.0001 and P<0.05), higher LVEF (P=0.0001), less frequent RFP (P=0.01), and lower pulmonary pressure (P<0.01). At follow-up (34+/-16 months), 21 patients had improved, while four had died and seven had received a transplant. Among clinical data, NYHA classes I-II (OR=0.25, P=0.07) and BB dosage (OR=0.97, P<0.005) were significantly associated with higher transplant-free survival at multivariate analysis. The addition of DET+ (OR=0.34, P<0.05) showed a moderate but significant improvement of sensitivity, but the predictive power of the model remained low (sensitivity, 0.67; specificity, 0.55). Absence of left bundle branch block (OR=0.27, P<0.01) and BB dosage (OR=1.03, P<0.005), but not DET+, were predictive of improvement. In patients with IDCM, DET response is associated with a more favourable outcome, since it suggests an earlier stage of the disease. However, in the light of our data, the incremental prognostic power of DET response compared to clinical evaluation at enrollment, despite being significant, seems to be of limited clinical value. Further studies should be carried out in order to clarify the prognostic value of DET in IDCM patients.

Using isoproterenol stress echocardiography to predict the response to carvedilol in patients with dilated cardiomyopathy

Trials have demonstrated that carvedilol can produce hemodynamic, symptomatic, and prognostic improvements in dilated cardiomyopathy (DCM), but some DCM patients have deteriorated after carvedilol, developing congestive heart failure. The present study investigated the use of isoproterenol (ISP) stress echocardiography to select those patients with DCM who would respond to carvedilol. ISP was infused intravenously in 22 patients with DCM and they were classified into 2 groups based on the left ventricular systolic response: good response to ISP [change in fractional shortening (FS) with ISP > 0.05, n=13] and poor response to ISP (change < or = 0.05, n=9). In the good response group, FS significantly increased from 0.12+/-0.04 to 0.17+/-0.08 (mean+/-SD, p<0.05) with carvedilol, and 7 patients improved symptomatically (New York Heart Association class). However, in the poor response group, no significant difference was observed between FS at baseline and that at the end of follow-up. Moreover, only 1 patient in the poor response group improved symptomatically. ISP stress echocardiography can assist in selecting patients with DCM who will respond positively to carvedilol.

Pacing for patients with congestive heart failure and dilated cardiomyopathy

Considerable evidence has now accumulated that permanent pacing may provide symptomatic benefit for at least some patients with CHF. Recently, the most promising results with left ventricular or biventricular pacing have been obtained. The data for improvement in survival with pacing is less compelling. The mortality of CHF associated with systolic dysfunction of the left ventricle remains high and arrhythmic deaths are frequent. Clinical trials such as the Sudden Cardiac Death Heart Failure Trial (SCD-HeFT) are currently underway to investigate the role of the implantable defibrillator in patients with heart failure. The development and general availability of ICDs with biventricular pacing capability may play an increasingly important role in the overall therapeutic plan for this group of patients to allow for optimization of functional status with pacing and protection from sudden cardiac death with defibrillation.

Long-term effects of carvedilol in idiopathic dilated cardiomyopathy with persistent left ventricular dysfunction despite chronic metoprolol. The Heart-Muscle Disease Study Group

OBJECTIVES

The purpose of this study was to analyze whether long-term treatment with the nonselective beta-adrenergic blocking agent carvedilol may have beneficial effects in patients with dilated cardiomyopathy (DCM), who are poor responders in terms of left ventricular (LV) function and exercise tolerance to chronic treatment with the selective beta-blocker metoprolol.

BACKGROUND

Although metoprolol has been proven to be beneficial in the majority of patients with heart failure, a subset of the remaining patients shows long-term survival without satisfactory clinical improvement.

METHODS

Thirty consecutive DCM patients with persistent LV dysfunction (ejection fraction < or =40%) and reduced exercise tolerance (peak oxygen consumption <25 ml/kg/min) despite chronic (>1 year) tailored treatment with metoprolol and angiotensin-converting enzyme inhibitors were enrolled in a 12-month, open-label, parallel trial and were randomized either to continue on metoprolol (n = 16, mean dosage 142+/-44 mg/day) or to cross over to maximum tolerated dosage of carvedilol (n = 14, mean dosage 74+/-23 mg/day).

RESULTS

At 12 months, patients on carvedilol, compared with those continuing on metoprolol, showed a decrease in LV dimensions (end-diastolic volume -8+/-7 vs. +7+/-6 ml/m2, p = 0.053; end-systolic volume -7+/-5 vs. +6+/-4 ml/m2, p = 0.047), an improvement in LV ejection fraction (+7+/-3% vs. -1+/-2%, p = 0.045), a reduction in ventricular ectopic beats (-12+/-9 vs. +62+/-50 n/h, p = 0.05) and couplets (-0.5+/-0.4 vs. +1.5+/-0.6 n/h, p = 0.048), no significant benefit on symptoms and quality of life and a negative effect on peak oxygen consumption (-0.6+/-0.6 vs. +1.3+/-0.5 ml/kg/min, p = 0.03).

CONCLUSIONS

In DCM patients who were poor responders to chronic metoprolol, carvedilol treatment was associated with favorable effects on LV systolic function and remodeling as well as on ventricular arrhythmias, whereas it had a negative effect on peak oxygen consumption.