SWISS II: Antiangina agents result in improved outcomes in patients with silent ischemia but without CAD

Key Points

Patients with silent ischemia but no coronary artery disease (CAD) may benefit from treatment with antianginal drug therapy, according to results of The Swiss Interventional Study on Silent Ischemia Type I (SWISS II).

This open-label pilot study sponsored by the Swiss Heart Foundation included 263 asymptomatic patients without prior CAD but with ≥ risk factor for CAD and confirmed silent ischemia (confirmed with exercise ECG followed by stress imaging).

Cardiac death, nonfatal myocardial infarction, and unstable angina requiring medical treatment or revascularization occurred in 12% of the patients taking antianginal medication and in 61% of those randomized to risk-factor control alone (P<.001). This was an absolute event reduction per year of 6.9% in favor of medical treatment, Dr Erne said.

The difference in outcomes occurred despite the majority of patients in the risk-factor control arm who successfully adhered to parameters; >60% of patients stopped smoking, ≤89% adhered to treatment for dyslipidemia, and a similar majority adhered to blood-pressure control regimens.

Furthermore, patients who received antianginal treatment had lower rates of exercise-induced ischemia during follow-up, and their ejection fraction remained unchanged from baseline. Patients participating in the risk-factor control arm however, experienced a 6.0% decrease in LVEF (P=.006), resulting in a significantly higher LVEF at final follow-up for those receiving antianginal treatment (61.1% vs 55.3%; P=.021).

"Drug therapy tended to reduce the signs of ischemia and to preserve left ventricular function. In patients with verified silent ischemia, prophylactic drug therapy should be considered," Dr Erne said.