Effects of Ivabradine on Residual Myocardial Ischemia After PCI

BACKGROUND. Residual angina after PCI is a frequently-occurring disease. Ivabradine improves symptoms but its role in patients without left-ventricular systolic dysfunction is still unclear. The aim was to quantify the effects of ivabradine in terms of MVO2 indicators and diastolic function.

METHODS. 28 consecutive patients with residual angina after PCI were randomized to ivabradine 5 mg twice/day(IG) or standard therapy(CG). All patients performed a stress echocardiography at the enrollment and after 30 days. Myocardial oxygen consumption was estimated from: double product(DP); triple product(TP) integrating DP with ejection-time(ET). Diastolic function was evaluated determining E and A waves, E' measurements and E/E' ratio both at rest and at the peak of exercise.

Inclusion criteria

• coronary artery disease with chronic stable angina for more than three months (Canadian Cardiovascular Society-CCS-class I-III);
• percutaneous revascularization with stent implantation at least one;
• signs/symptoms of residual ischemia; sinus rhythm; HR ≥ 70 bpm at rest;
• ability to perform an echocardiogram stress test with the tilting bicycle stress test (BST);
• good acoustic window;
• age ≥ 18 years.

Exclusion criteria

• drugs intolerance or hypersensitivity
• EF ≤ 40 %
• NYHA class III to IV;
• CCS IV
• atrial fibrillation or flutter
• presence of a pacemaker or implantable defibrillator
• II or III degree AV block
• HR ≤ 70 bpm at rest or sick sinus syndrome
• any condition that could interfere with the ability to exercise stress test like Wolff- Parkinson-White syndrome, left bundle branch block, left ventricular hypertrophy;
• rate-corrected QT interval (QTc) greater than 500 ms or the use of drugs that prolong the QTc interval
• symptomatic hypotension or uncontrolled hypertension (systolic blood pressure at rest ≥ 180 mmHg or diastolic blood pressure ≥ 100 mmHg)
• severe liver disease and severe renal impairment (creatinine clearance ≤ 30 ml/min)
• electrolyte disorders
• uncontrolled thyroid disease
• pregnancy.