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. (Am Heart J 2011;161:878-85.)