Left Ventricular Hypertrophy with Strain and Aortic Stenosis
Background—Electrocardiographic (ECG) left ventricular hypertrophy (LVH) with strain is associated with an adverse prognosis in aortic stenosis. We investigated the mechanisms and outcomes associated with ECG-strain.
Methods and Results—One hundred and two patients (70 [63,75] years, 66% males, aortic valve area 0.9 [0.7,1.2] cm2) underwent ECG, echocardiography and cardiovascular magnetic resonance: the Mechanism Cohort. Myocardial fibrosis was determined using late gadolinium enhancement (LGE, replacement fibrosis) and T1 mapping (diffuse fibrosis). The relationship between ECG-strain and CMR was then assessed in an external Validation Cohort (n=64). The Outcome Cohort comprised of 140 patients from the Scottish Aortic Stenosis and Lipid Lowering Trial Impact on REgression (SALTIRE) study and followed up for 10.6 years (1,254 patient-years). Compared to those without LVH (n=51) and LVH without ECG-strain (n=30), patients with ECG-strain (n=21) had more severe aortic stenosis, increased left ventricular mass index, more myocardial injury (high-sensitivity plasma cardiac troponin I concentration 4.3 [2.5,7.3] versus 7.3 [3.2,20.8] versus 18.6 [9.0,45.2] ng/L respectively, P<0.001) and increased diffuse fibrosis (extracellular volume fraction 27.4±2.2 versus 27.2±2.9 versus 30.9±1.9% respectively, P<0.001). All patients with ECG-strain had mid-wall LGE (positive and negative predictive values of 100% and 86%, respectively). Indeed, LGE was independently associated with ECG-strain (OR 1.73, 95%CI 1.08-2.77, P=0.02): a finding confirmed in the Validation Cohort. In the Outcome Cohort, ECG-strain was an independent predictor of aortic valve replacement or cardiovascular death (HR 2.67, 95%CI 1.35-5.27, P<0.01).
Conclusions—ECG-strain is a specific marker of mid-wall myocardial fibrosis and predicts adverse clinical outcomes in aortic stenosis.
- Received May 8, 2014.
- Revision received August 12, 2014.
- Accepted August 25, 2014.