Impact of left ventricular hypertrophy on myocardial injury in patients with ST-segment elevation myocardial infarction

Background: Left ventricular hypertrophy (LVH) has been suggested as a determinant of outcome in patients with ST-segment elevation myocardial infarction (STEMI). However, available data are inconclusive and the underlying mechanisms remain unclear. Therefore, the aim of this study was to evaluate the impact of LVH on myocardial injury and clinical outcome in a large multicenter STEMI population. Methods: Cardiovascular magnetic resonance was performed in 795 patients within 10 days after STEMI to assess left ventricular (LV) mass and parameters of myocardial injury. Gender-specific cutoff values of indexed LV mass were used to define LVH (67 g/m ² for men and 61 g/m ² for women). Rates of major adverse cardiac events (MACE) were determined at 12-month follow-up. Results: LVH was present in 438 patients (55%) and associated with a significantly larger infarct size [18.3% of LV mass (%LV) versus 14.0%LV; p < 0.01], a lower myocardial salvage index (47.8 versus 54.4; p < 0.01), larger extent of microvascular obstruction (0.4 versus 0%LV; p < 0.01) and lower LV ejection fraction (47.9 versus 53.2%; p < 0.01) compared to STEMI patients without LVH. The effect of LVH on LV ejection fraction, infarct size and myocardial salvage index remained statistically significant after adjustment for baseline characteristics (p < 0.01 for all). MACE rates at 12 months were numerically higher in patients with versus without LVH without reaching statistical significance (7.5 versus 5.6%; p = 0.32). Conclusion: In STEMI patients, LVH is associated with more pronounced structural and functional alterations in CMR imaging as an indicator for adverse clinical outcomes in STEMI survivors.