Five-Year Outcomes and Prognostic Value of Feature-Tracking Cardiovascular Magnetic Resonance in Patients Receiving Early Prereperfusion Metoprolol in Acute Myocardial Infarction.

Abstract

The aim of the present study was to investigate the long-term impact of early intravenous metoprolol in ST-segment elevation myocardial infarction (STEMI) patients in terms of left ventricular (LV) strain with feature-tracking cardiovascular magnetic resonance (CMR) and its association with prognosis. A total of 270 patients with first anterior STEMI enrolled in the randomized METOCARD-CNIC clinical trial, assigned to receive up to 15 mg intravenous metoprolol before primary percutaneous coronary intervention versus conventional STEMI therapy, were included. LV global circumferential (GCS) and longitudinal (GLS) strain were assessed with feature-tracking CMR at 1 week after STEMI in 215 patients. The occurrence of major adverse cardiac events (MACE) at 5-year follow-up was the primary end point. Among 270 patients enrolled, 17 of 139 patients assigned to metoprolol arm and 31 of 131 patients assigned to control arm experienced MACE (hazard ratio [HR] 0.500, 95% confidence interval [CI] 0.277 to 0.903; p = 0.022). Impaired LV GCS and GLS strain were significantly associated with increased occurrence of MACE (GCS: HR 1.208, 95% CI 1.076 to 1.356, p =0.001; GLS: HR 1.362, 95% CI 1.180 to 1.573, p < 0.001). On multivariable analysis, LV GLS provided incremental prognostic value over late gadolinium enhancement (LGE) and LV ejection fraction (LVEF) (LGE + LVEF chi-square = 12.865, LGE + LVEF + GLS chi-square = 18.459; p =0.012). Patients with GLS ≥-11.5% (above median value) who received early intravenous metoprolol were 64% less likely to experience MACE than their counterparts with same degree of GLS impairment (HR 0.356, 95% CI 0.129 to 0.979; p = 0.045). In conclusion, early intravenous metoprolol has a long-term beneficial prognostic effect, particularly in patients with severely impaired LV systolic function. LV GLS with feature-tracking CMR early after percutaneous coronary intervention offers incremental prognostic value over conventional CMR parameters in risk stratification of STEMI patients.