ACE inhibitors in coronary artery disease

ACE inhibitors in coronary artery disease

ACE inhibitors in coronary artery disease: The most important beneficial effect of angiotensin converting enzyme (ACE) inhibitors is prevention of adverse cardiovascular remodeling after a myocardial infarction. Ventricular remodeling consists of infarct expansion and dilatation of rest of the ventricle. Though initially this is beneficial by increasing force of myocardial contraction and hence the cardiac output (Starling’s law of the heart: force of contraction is proportional to the myocardial fibre length).

SOLVD Investigators; Salim Yusuf, Bertram Pitt, Clarence E Davis, William B Hood, Jay N Cohn randomly assigned 1284 patients on conventional treatment for heart failure to placebo and 1285 patients to enalapril [1]. Fewer patients died or were hospitalized for worsening of heart failure on enalapril (613 vs 736, P < 0.0001). The authors concluded that enalapril therapy significantly reduced mortality and hospitalizations for heart failure in patients with chronic heart failure and reduced ejection fractions.

In addition to the important effect on prevention of ventricular remodeling, ACE inhibitors are thought to have some antiatherogenic effects also. They also produce a favourable alteration of the fibrinolytic balance and causes neurohormonal modulation. Thus ACE inhibitors could be used to prevent secondary coronary events after a myocardial infarction. Benefits of ACE inhibitors are more in those with highest risk, viz: those with anterior wall myocardial infarction, previous infarction, heart failure and tachycardia.

Contraindications for ACE inhibitors

In the following situations ACE inhibitors are contraindicated:

1. High risk of further serious hemodynamic deterioration
2. History of clinically relevant renal failure (serum creatinine > 3 mg/dl)
3. History of bilateral stenosis of the renal arteries
4. Documented allergy to ACE inhibitors
5. Pregnancy – fetal toxicity

Reference

1. SOLVD Investigators; Salim Yusuf, Bertram Pitt, Clarence E Davis, William B Hood, Jay N Cohn. Effect of enalapril on survival in patients with reduced left ventricular ejection fractions and congestive heart failure. N Engl J Med. 1991 Aug 1;325(5):293-302.