Heart rate and left ventricular adverse remodelling after ST-elevation myocardial infarction.

BACKGROUND: Discharge heart rate (HR) following ST-elevation myocardial infarction (STEMI) is a predictor of adverse left ventricular remodelling (LVR). However, the prognostic relevance of HR values in the earlier phase after revascularization is unknown. We aimed to investigate resting HR assessed at different time points during hospital stay following STEMI for the prediction of LVR.

METHODS: In this prospective observational study of 143 consecutive STEMI patients, HR was measured serially on admission (AHR), at day 1 (HRd1) and 2 (HRd2) following revascularization and finally at discharge (DHR). Cardiac magnetic resonance (CMR) scans were performed at baseline and 4months thereafter to evaluate LVR and major CMR determinants of LVR (infarct size, microvascular obstruction). LVR was defined as ≥15% increase of left ventricular end-diastolic volume.

RESULTS: Twenty-nine patients (20%) have developed LVR. HRd1 (80[72-88] vs. 71[62-79]bpm, p=0.003), HRd2 (74[64-83] vs. 67[59-78]bpm, p=0.04), DHR (74[62-81] vs. 64[58-73] bpm, p=0.008) and the mean HR of all measurements (76[68-82] vs. 67[60-77]bpm, p=0.004) were significantly higher in patients with LVR, whereas admission HR (75[68-85] vs. 70[60-82]bpm, p=0.12) did not differ significantly. The associations for all post-admission HRs remained significant after adjustment for clinical (high-sensitivity cardiac troponin T and C-reactive protein, left anterior descending artery as culprit) and CMR (infarct size, microvascular obstruction, ejection fraction) predictors of LVR. The predictive values of the post-admission HRs were equivalent (area under the curve differences: all p>0.05).

CONCLUSION: Besides DHR, resting HR values in the early stage following reperfusion are independent predictors of LVR after STEMI.