Effects of percutaneous coronary interventions in silent ischemia after myocardial infarction: the SWISSI II randomized controlled trial.
BACKGROUND
The effect of a percutaneous coronary intervention (PCI) on the long-term prognosis of patients with silent ischemia after a myocardial infarction (MI) is not known.


OBJECTIVE
To determine whether PCI compared with drug therapy improves long-term outcome of asymptomatic patients with silent ischemia after an MI.


METHODS
Randomized, unblinded, controlled trial (Swiss Interventional Study on Silent Ischemia Type II [SWISSI II]) conducted from May 2, 1991, to February 25, 1997, at 3 public hospitals in Switzerland of 201 patients with a recent MI, silent myocardial ischemia verified by stress imaging, and 1- or 2-vessel coronary artery disease. Follow-up ended on May 23, 2006.


METHODS
Percutaneous coronary intervention aimed at full revascularization (n = 96) or intensive anti-ischemic drug therapy (n = 105). All patients received 100 mg/d of aspirin and a statin.


METHODS
Survival free of major adverse cardiac events defined as cardiac death, nonfatal MI, and/or symptom-driven revascularization. Secondary measures included exercise-induced ischemia and resting left ventricular ejection fraction during follow-up.


RESULTS
During a mean (SD) follow-up of 10.2 (2.6) years, 27 major adverse cardiac events occurred in the PCI group and 67 events occurred in the anti-ischemic drug therapy group (adjusted hazard ratio, 0.33; 95% confidence interval, 0.20-0.55; P<.001), which corresponds to an absolute event reduction of 6.3% per year (95% confidence interval, 3.7%-8.9%; P<.001). Patients in the PCI group had lower rates of ischemia (11.6% vs 28.9% in patients in the drug therapy group at final follow-up; P = .03) despite fewer drugs. Left ventricular ejection fraction remained preserved in PCI patients (mean [SD] of 53.9% [9.9%] at baseline to 55.6% [8.1%] at final follow-up) and decreased significantly (P<.001) in drug therapy patients (mean [SD] of 59.7% [11.8%] at baseline to 48.8% [7.9%] at final follow-up).


CONCLUSIONS
Among patients with recent MI, silent myocardial ischemia verified by stress imaging, and 1- or 2-vessel coronary artery disease, PCI compared with anti-ischemic drug therapy reduced the long-term risk of major cardiac events.


BACKGROUND
clinicaltrials.gov Identifier: NCT00387231.
Erne
Paul
P
Division of Cardiology, Kantonsspital Luzern, Luzern, Switzerland. Paul.Erne@ksl.ch
Schoenenberger
Andreas W
AW
Burckhardt
Dieter
D
Zuber
Michel
M
Kiowski
Wolfgang
W
Buser
Peter T
PT
Dubach
Paul
P
Resink
Therese J
TJ
Pfisterer
Matthias
M
D015906:Angioplasty, Balloon, Coronary; D003324:Coronary Artery Disease / Q000628:therapy; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000628:therapy; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000628:therapy*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D011379:Prognosis; D016016:Proportional Hazards Models; D011875:Radionuclide Angiography; D014665:Vasodilator Agents / Q000627:therapeutic use
D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010975:Platelet Aggregation Inhibitors; D014665:Vasodilator Agents