Re: The PEP-CHF study

Management of diastolic heart failure--a practical review of pathophysiology and treatment trial data

The lack of large randomised controlled trials to guide therapy in diastolic heart failure causes some difficulties for evidence-based medicine practising clinicians. Traditionally, treatments for systolic heart failure have been highjacked for diastolic heart failure without much proof of benefit. However, recent studies have began to provide some evidence base for our practice. Betablockers and angiotensin receptor antagonists have recently been shown to reduce hospitalisation in large randomised controlled trials. Diuretic based antihypertensive regimes have been shown to reduce heart failure by 50%. Left ventricular hypertrophy regression is likely to be a good surrogate endpoint for diastolic heart failure, although definitive proof for this is not yet available. Angiotensin receptor antagonists, ACEI, calcium channel blockers, diuretics and aldosterone blockers have all been shown to cause left ventricular hypertrophy regression. We recommend these drugs to achieve strict blood pressure control together with dietary and lifestyle modification for the treatment of diastolic heart failure. We emphasise the importance of rate control, as diastolic heart-failure patients tolerate tachycardia poorly. We further argue that the pathophysiology of diastolic heart failure is part of systolic heart failure and the two should not be thought of as separate entities. Therefore, our traditional practice of using systolic heart failure treatments for diastolic heart failure is theoretically sound and should not cause us undue anxiety.

Rationale and Design of a Randomized Trial to Assess the Effects of β-blocker in Diastolic Heart Failure; Japanese Diastolic Heart Failure Study (J-DHF)

BACKGROUND

Heart failure consists of two phenotypes: systolic heart failure and diastolic heart failure (DHF). A growing body of evidence demonstrated benefits of beta-blocker, angiotensin-converting enzyme inhibitor, and angiotensin II receptor blocker in systolic heart failure; however, evidence leading to therapeutic strategy of DHF is lacking.

METHODS AND RESULTS

The Japanese Diastolic Heart Failure Study (J-DHF) is a multicenter, prospective, randomized trial designed to assess effects of beta-blocker in patients with DHF. A total of 800 patients (400 patients in each group) will be enrolled. The primary outcome is a composite of cardiovascular death and unplanned admission to hospital for congestive heart failure. Other outcomes include all-cause mortality, worsening of the symptoms of heart failure, or a need for modification of the treatment for heart failure. Serial assessment of echocardiographic and neurohumoral parameters and cost analysis of the treatment regimen will be conducted. The follow-up period is a minimum of 2 years.

CONCLUSION

This study will provide important evidences for the treatment of DHF.

A phase II, double-blind, randomized, placebo-controlled, dose comparative study of the efficacy, tolerability, and safety of MCC-135 in subjects with chronic heart failure, NYHA class II/III (MCC-135-GO1 study): rationale and design

BACKGROUND

Chronic heart failure (CHF) can be caused either by a predominant abnormality in systolic function (systolic heart failure) or a predominant abnormality in diastolic function (diastolic heart failure). Randomized clinical trials have identified a number of pharmaceutical agents that can reduce morbidity and mortality in patients with systolic heart failure. Despite significant therapeutic advances, systolic heart failure continues to result in high rates of morbidity and mortality. In contrast to systolic heart failure, no randomized clinical trials have been performed in patients with diastolic heart failure. Common to the mechanisms causing both systolic and diastolic heart failure are abnormalities in calcium homeostasis. Mitsubishi Pharma Corporation has developed a compound (MCC-135, INN; caldaret) whose mechanism of action is proposed to be modulation of calcium homeostasis at the sarcoplasmic reticulum and cellular membrane. The purpose of this study was to test the safety, tolerability, and efficacy of MCC-135 in patients with mild to moderate heart failure.

METHODS

This was a phase II, multicenter, randomized, double-blind study of parallel group design comparing 3 oral dose regimens of MCC-135 (5 mg, 25 mg, 50 mg, twice daily) with a placebo control. The treatment period was 24 weeks. A total of 511 patients were recruited from 69 centers in the United States and Europe. One hundred and twenty-five patients were recruited in each of the 4 treatment groups. Patients in each treatment group were divided into 2 cohorts: those with an ejection fraction < or = 40%, and those with an ejection fraction >40% as determined by core laboratory analysis of echocardiographic studies.

CONCLUSION

Patient recruitment was completed in September 2002. Patient follow-up was completed by February 2003; the results will be available for release in 2004.

Diastolic heart failure: a difficult problem in the elderly

Heart failure with normal systolic function has been equated to diastolic heart failure (DHF). DHF appears to be quite common in the elderly, especially in elderly women with hypertension. Recent epidemiologic studies suggest that 30%-50% of patients with heart failure may have DHF. Morbidity for DHF is considerable and comparable to that of heart failure with left ventricular systolic dysfunction. Both groups of patients have similar rates of recurrent hospitalization and cost of care. Long-term mortality also appears to be similar in the two groups of patients. With the aging of the population, the numbers of patients with DHF will continue to rise and are likely to contribute significantly to the burden of disease caused by heart failure. Unfortunately, as yet, no reliable definition has been found for DHF. Currently the diagnosis of DHF is often made by exclusion, and treatment is empirical and unsatisfactory because of the lack of large-scale, randomized, controlled trials in this area; however, several large and other smaller trials are currently in progress that will hopefully provide some answers.

Diagnosing diastolic heart failure

BACKGROUND

increasing evidence supports the existence of left ventricular diastolic dysfunction as an important cause of congestive heart failure, present in up to 40% of heart failure patients.

AIM

to review the pathophysiology of LV diastolic dysfunction and diastolic heart failure and the currently available methods to diagnose these disorders.

RESULTS

for diagnosing LV diastolic dysfunction, invasive hemodynamic measurements are the gold standard. Additional exercise testing with assessment of LV volumes and pressures may be of help in detecting exercise-induced elevation of filling pressures because of diastolic dysfunction. However, echocardiography is obtained more easily, and will remain the most often used method for diagnosing diastolic heart failure in the coming years. MRI may provide noninvasive determination of LV three-dimensional motion during diastole, but data on correlation of MRI data with clinical findings are scant, and possibilities for widespread application are limited at this moment.

CONCLUSIONS

in the forthcoming years, optimal diagnostic and therapeutic strategies for patients with primary diastolic heart failure have to be developed. Therefore, future heart failure trials should incorporate patients with diastolic heart failure, describing precise details of LV systolic and diastolic function in their study populations.

Diastolic heart failure: neglected or misdiagnosed?

Recent epidemiological studies suggest that 30% to 50% of patients with heart failure (HF) have preserved left ventricular (LV) systolic function. These patients, often presumed to have diastolic heart failure (DHF), appear to have lower short-term but similar long-term mortality when compared to patients with HF and LV systolic dysfunction. Rates of recurrent hospitalization and costs of care appear similar in the two groups of patients. Therefore, DHF may contribute significantly to the burden of disease caused by HF. Exertional breathlessness, the principal symptom of HF, has many causes, including obesity, pulmonary disease and myocardial ischemia. A diagnosis of DHF by exclusion, based on symptoms in the absence of important LV systolic dysfunction or major valve disease, is unsatisfactory. Unfortunately, as yet, no reliable definition with which to make a positive diagnosis of DHF has been agreed on, frequently rendering this diagnosis uncertain. Echocardiography has several limitations, whereas hemodynamic confirmation of DHF by cardiac catheterization is potentially complex and not practically feasible for many patients. Treatment of DHF remains empirical and unsatisfactory because of the lack of large-scale randomized controlled trials in this area. Currently, three large outcome studies on DHF are in progress along with other smaller trials. These should start to provide some of the answers we need to diagnose and effectively treat DHF.