ISCHEMIA TRIAL

Background: We don't know the optimum mode of therapy for patients with stable ischemic heart disease along with moderate to severe myocardial ischemia on non-invasive stress testing. Routine early invasive therapy was compared with optimal medical therapy in this trial.

Study design:
Patients: Stable ischemic heart disease with moderate to severe ischemia on stress testing.

All patients underwent CT coronary angiogram prior to inclusion in the trial to rule out significant LM disease.

Exclusion:
- LM stenosis >50% (on CT coronary angiogram)
- Recent MI
- LVEF < 35%
- Unacceptable angina at baseline
- NYHA class III and IV heart failure
- Prior PCI or CABG within last one year

Groups: Routine invasive therapy (n = 2588) vs initial optimal medical therapy (n= 2591)

Interventions in both groups:
- Routine invasive group: Patients underwent angiography followed by PCI or CABG as per the anatomy.
- Medical therapy group: All patients were put on initial medical therapy and they underwent angiography only upon failure of medical therapy.

Mean duration of follow-up: 3.3 years

Outcomes:
- Primary outcome (composite of cardiovascular mortality, MI, or hospitalization for unstable angina or heart failure) at the end of the study period:
13.3% in routine invasive group vs. 15.5% in medical therapy group (p=0.34).
- Secondary outcomes:
Cardiovascular death or MI: Not different
All-cause mortality: Not different
Spontaneous MI: Not different

Clinical relevance:
- Routine invasive therapy did not reduce major adverse cardiac events (Myocardial infarction, cardiovascular mortality, and all-cause mortality) compared to the initial optimal medical therapy approach in patients with stable ischemic heart disease with moderate to severe ischemia on stress testing.
- The patients with recent ACS, highly symptomatic patients, significant left main disease, or severe LV dysfunction (LVEF < 35%) were excluded from the trial, so the results should not be extended to such patients.

Reference: https://www.nejm.org/doi/full/10.1056/NEJMoa1915922