Long-Term Outcome of the Randomized DAPA Trial.

BACKGROUND

The randomized DAPA trial (Defibrillator After Primary Angioplasty) aimed to evaluate the survival benefit of prophylactic implantable cardioverter defibrillator (ICD) implantation in early selected high-risk patients after primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction.

METHODS

A randomized, multicenter, controlled trial compared ICD versus conventional medical therapy in high-risk patients with primary percutaneous coronary intervention, based on one of the following factors: left ventricular ejection fraction <30% within 4 days after ST-segment-elevation myocardial infarction, primary ventricular fibrillation, Killip class ≥2 or TIMI (Thrombolysis in Myocardial Infarction) flow <3 after percutaneous coronary intervention. ICD was implanted 30 to 60 days after MI. Primary end point was all-cause mortality at 3 years follow-up. The trial prematurely ended after inclusion of 266 patients (38% of the calculated sample size). Additional survival assessment was performed in February 2019 for the primary end point.

RESULTS

A total of 266 patients, 78.2% males, with a mean age of 60.8±11.3 years, were enrolled. One hundred thirty-one patients were randomized to the ICD arm and 135 patients to the control arm. All-cause mortality was significant lower in the ICD group (5% versus 13%, hazard ratio, 0.37 [95% CI, 0.15-0.95]) after 3 years follow-up. Appropriate ICD therapy occurred in 9 patients at 3 years follow-up (5 within the first 8 months after implantation). After a median long-term follow-up of 9 years (interquartile range, 3-11), total mortality (18% versus 38%; hazard ratio, 0.58 [95% CI, 0.37-0.91]), and cardiac mortality (hazard ratio, 0.52 [95% CI, 0.28-0.99]) was significant lower in the ICD group. Noncardiac death was not significantly different between groups. Left ventricular ejection fraction increased ≥10% in 46.5% of the patients during follow-up, and the extent of improvement was similar in both study groups.

CONCLUSIONS

In this prematurely terminated and thus underpowered randomized trial, early prophylactic ICD implantation demonstrated lower total and cardiac mortality in patients with high-risk ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention. Registration: URL: https://www.trialregister.nl; Unique identifier: Trial NL74 (NTR105).