Prognostic significance of electrocardiographic-determined left ventricular hypertrophy and associated ST-segment depression in patients with non-ST-elevation acute coronary syndromes

Background: Left ventricular hypertrophy (LVH) is frequently associated with ST depression (STD) on the electrocardiogram (ECG), a so-called strain pattern. Although STD is a well-established adverse prognosticator in non-ST-elevation acute coronary syndrome (NSTE-ACS), the relative prognostic importance of LVH and associated STD has not been elucidated.

Methods: A total of 7,761 patients with NSTE-ACS in the Global Registry of Acute Coronary Events (GRACE) and ACS-I registries had admission ECGs analyzed at a core laboratory. Left ventricular hypertrophy (determined by Sokolow-Lyon and/or Casale criteria) was observed in 296 (3.8%) patients. We examined the independent association between LVH (determined by the admission ECG) and outcomes in relation to STD.

Results: Patients with LVH were older, had more comorbidities and STD, and presented with a higher Killip class. They were less likely to undergo cardiac catheterization (43.1% vs 51.2%, P = .006) and percutaneous coronary intervention (18.3% vs 24.6%, P = .014). Patients with LVH had higher unadjusted mortality at 6 months (10.5% vs 7.1%, P = .038), but similar rates of in-hospital mortality (4.1% vs 3.4%, P = .54) and reinfarction (7.1% vs 7.6%, P = .75). Patients with LVH were more likely to have heart failure in-hospital (21.8% vs 11.8%, P < .001). Among LVH patients, degree of quantitative STD did not predict higher short- or long-term mortality, but was associated with in-hospital heart failure. Multivariable analysis adjusting for other clinical prognosticators of the GRACE risk models revealed that LVH was not a significant independent predictor of in-hospital mortality (adjusted odds ratio = 0.75, 95% CI 0.40-1.41, P = .37) or 6-month mortality (adjusted odds ratio = 0.83, 95% CI 0.52-1.35, P = .44). In contrast, STD remained a strong independent predictor of adverse outcomes. There was no significant interaction between STD and LVH.

Conclusions: Across the broad spectrum of NSTE-ACS, LVH is associated with adverse prognostic factors including STD. Electrocardiographic-determined LVH provides no significant additional prognostic utility beyond comprehensive risk assessment using the GRACE risk score. The adverse prognosis associated with LVH in NSTE-ACS may be attributable to other prognosticators such as STD.