[The renin-angiotensin system in cardiovascular diseases]

ACE Inhibition versus Angiotensin-II Antagonism in Heart Failure

Heart failure is becoming increasingly frequent. Once diagnosed, 5-year survival is less than 50% and a substantial percentage of patients (25% to 50%) die suddenly. Angiotensin-converting enzyme inhibitors are the only agents shown to reduce mortality in heart failure. All angiotensin-converting enzyme inhibitors appear to have similar clinical benefits in heart failure. Therapy should be started with a low dose and titrated up to the target dosage in major trials. Although angiotensin-I receptor antagonists provide more complete inhibition of angiotensin-II effects, they have not been found to be superior to long-acting angiotensin-converting enzyme inhibitors in reducing morbidity and mortality in heart failure. Therefore, in current clinical practice, angiotensin-II antagonists should be used as an alternative to angiotensin-converting enzyme inhibitors when the latter are not tolerated. The combined use of angiotensin-converting enzyme inhibitors and angiotensin-II antagonists is not currently recommended in the treatment of heart failure.

Serial analysis of troponin I levels in patients with ischemic and nonischemic dilated cardiomyopathy

BACKGROUND

Ongoing myocardial cell damage forms the basis for progression of chronic heart failure. Evidence is accumulating that progressive loss of cardiac myocytes is associated with the release of cardiac troponin I (cTnI).

HYPOTHESIS

This study sought to determine whether levels of cTnI are of prognostic value for risk stratification of patients with chronic heart failure.

METHODS

Release of cTnI was measured by conventional enzyme immunoassay following serum ultrafiltration in 58 consecutive patients hospitalized for chronic heart failure and 31 healthy volunteers serving as control group. Determination of serum levels was performed every 2 weeks over a time interval of 3 months. According to the results of coronary angiography, patients were divided into Group D showing normal coronary arteries (n=33, ejection fraction 27 +/- 6.1%) and Group I showing severe coronary heart disease (n=25, ejection fraction 28.8 +/- 7.8%). Survival of patients was evaluated after a mean time interval of 3 years.

RESULTS

The mean cTnI serum level over all measurements was 0.66 +/- 1.8 ng/ml in patients versus 0.11 +/- 0.48 ng/ml in volunteers. At all six points of analysis, the mean cTnI serum level was significantly different (p < 0.001) between patients and volunteers. There was no significant difference between patients with and without coronary heart disease following hospital discharge, however, troponin release was significantly different between survivors and nonsurvivors (n=27) (0.56 ng/ml vs. 0.84 ng/ml; p < 0.05).

CONCLUSION

Permanent cTnI release is a common finding in patients with chronic heart failure and a strong prognosticator. In this setting, coronary morphology seems to play a minor role for disease progression.

The kidney in congestive heart failure: renal adverse event rate of treatment

In this paper we review the effect of medical treatment on renal function in patients with congestive heart failure. We have examined data from the large-scale heart failure studies with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, beta-receptor blockers, an aldosterone antagonist, and a vasopeptidase inhibitor. Renal outcome was reported in almost all of the studies with angiotensin-converting enzyme inhibitors. Despite concern about renal adverse events with drugs in this class, they seem to be safe in patients with congestive heart failure. In contrast, we did not find any report about renal function in patients treated with beta-receptor blockers for congestive heart failure.