Background:
Left ventricular hypertrophy (LVH) is an established risk factor for heart failure (HF). However, it is unknown whether LVH detected by electrocardiogram (ECG-LVH) is equivalent to LVH ascertained by cardiac magnetic resonance imaging (MRI-LVH) in terms of prediction of incident HF using risk prediction models like the Framingham Heart Failure Risk Score (FHFRS).
Methods:
This analysis included 4745 (mean age 61+10 years, 53.5% women, 61.7% non-whites) from the Multi-Ethnic Study of Atherosclerosis who were free of cardiovascular disease at the time of enrollment. ECG-LVH was defined using Cornell’s criteria while MRI-LVH was derived from left ventricular (LV) mass measured by cardiac MRI. Cox proportional hazard regression was used to examine the association between ECG-LVH and MRI-LVH with incident HF. Harrell’s concordance C-index was used to estimate the predictive ability of the FHFRS when either ECG-LVH or MRI-LVH were included as one of its components. The added predictive ability of ECG-LVH and MRI-LVH were investigated using integrated discrimination improvement (IDI) index and relative IDI.
Results:
ECG-LVH was present in 291(6.1%) while MRI-LVH was present in 499 (10.5%) of the participants. Over a median follow up of 10.4 years, 140 participants developed HF. Both ECG-LVH [HR (95% CI): 2.25(1.38-3.69)] and MRI-LVH [HR (95% CI): 3.80(1.56-5.63)] were associated with an increased risk of HF in multivariable adjusted models (Table 1). The ability of FHFRS to predict HF was improved with MRI-LVH (C-index 0.871, 95% CI: 0.842-0.899) when compared with ECG-LVH (C-index 0.860, 95% CI: 0.833-0.888) (p < 0.0001). To assess the potential clinical utility of using LVH-MRI instead of ECG-LVH, we calculated several measures of reclassification (Table 1), which were consistent with the statistically significantly improved C-statistic with MRI-LVH.
Conclusion:
Both ECG-LVH and MRI-LVH are predictive of HF when used in the FHFRS. Substituting MRI-LVH for ECG-LVH improves the predictive ability of the FHFRS.
Evaluation of the use of unipolar voltage amplitudes for detection of myocardial scar assessed by cardiac magnetic resonance imaging in heart failure patients
