Expert position paper on prolonged dual antiplatelet therapy in secondary prevention following myocardial infarction

Abstract

The protective effect of dual antiplatelet therapy (DAPT) following acute coronary syndrome is undisputed, but its duration is subject of debate. Several studies show that prolonged therapy provides a clinical benefit in patients following acute coronary syndrome. The aim of this position paper authored by Austrian experts is to outline the current evidence and provide an overview of recent studies. It is also intended to serve as a practical guide to identify those patients who may benefit from prolonged DAPT.

Keywords: Acute coronary syndrome; DAPT; Myocardial infarction; P2Y12 inhibitor; Ticagrelor.

Fig. 1

Recent changes in recommendations of prolonged dual antiplatelet therapy in international guidelines. ESC European Society of Cardiology, STE-ACS ST-Segment Elevation Acute Coronary Syndrome, ACS Acute Coronary Syndrome, NSTE-ACS Non-ST-Segment Elevation Acute Coronary Syndrome, DAPT Dual Antiplatelet Therapy, BMS Bare Metal Stent, DES Drug Eluting Stent, STEMI ST-Segment Elevation Myocardial Infarction, PCI Percutaneous Coronary Intervention, ASA Acetylic Salicylic Acid, ACCF American College of Cardiology Foundation, AHA American Heart Association

Fig. 2

Kaplan–Meier risk (nonfatal MI or coronary death) for stable angina patients (n = 45,645), STEMI (n = 4,700) and NSTEMI (n = 6,818). For ACS patients, follow-up started 6 months after index event. Mean follow-up time was 4.4 years. Adapted from [9] CHD coronary heart disease, MI myocardial infarction, NSTEMI non-ST-elevation myocardial infarction, STEMI ST-elevation myocardial infarction

Fig. 3

Patients were randomized 1–3 years (median 1.7 years) after index myocardial infarction (MI). Kaplan–Meier rates of cardiovascular death, myocardial infarction, or stroke over 3 years were 9.04 % in the placebo group and 7.85 % in the group that received 90 mg ticagrelor twice daily (BI D; vs placebo HR 0.85; 95 % CI 0.75–0.96; p = 0.008) and 7.77 % in the group that received 60 mg ticagrelor twice daily (vs placebo HR 0.84; 95 % CI 0.74–0.95; p = 0.004). Adapted from [17]. ACS acute coronary syndrome

Fig. 4

Effects of ticagrelor 60 mg twice daiy + ASA versus placebo + ASA on the combined primary efficacy endpoint (CV death, MI, stroke) and individual components. After [17]. CV cardiovascular, MI myocardial infarction, ASA acetylsalicylic acid, CI confidence interval

Fig. 5

Cumulative event rates of TIMI major bleeding at 3 years were 1.06 % in the placebo group, 2.6 % in the ticagrelor 90 mg twice daily group and 2.3 % in the ticagrelor 60 mg twice daily group. The 3 year Kaplan–Meier (KM) rates for fatal bleeding or intracranial haemorrhage (ICH) were 0.6, 0.63 and 0.71 %, respectively. n.s. not significant, TIMI Thrombolysis in Myocardial Infarction

Fig. 6

a Timeline of patients enrolled in trial. After the qualifying ACS patients were treated with DAPT independent of the study. After DAPT withdrawal patients were treated with ASS monotherapy until randomization to ticagrelor or placebo. b Analysis of 3‑year rate of efficacy endpoint (CV death, stroke, MI) according to time from last P2Y₁₂ inhibitor to randomization (= ASA monotherapy phase). days: ≤ 30, > 30–360, > 360. Data is shown for ticagrelor 60 mg twice daily vs placebo. Adapted from [20]. ASA acetylsalicylic acid, ACS acute coronary syndrome, DAPT dual antiplatelet therapy, HR hazard ratio, RRR relative risk reduction

Fig. 7

Careful evaluation of the cardiovascular risk factors and bleeding risk factors should determine the recommendation of DAPT duration at the time of discharge from the hospital after MI. OAC oral anticoagulation, PAD peripheral artery disease