Abstract 3777: Strong Prognostic Implication of Left Atrial Conduit and Pump Functions Assessed by Cardiac Magnetic Resonance in Hypertensive Patients At Risk for Diastolic Dysfunction
Background: Patients with hypertensive cardiomyopathy are at increased risk of major adverse cardiac events (MACE) despite preserved left ventricular (LV) systolic function. Left atrial (LA) size has been proposed to be a load-insensitive marker of hemodynamic diastolic impairment of the LV. We tested the hypothesis that impaired conduit and pump functions of the LA during ventricular diastole assessed by cardiac MRI (CMR) are associated with MACE. We further examined the prognostic association between 2 LA sizing methods, one with and one without geometric assumptions.
Methods: 185 hypertensive patients without evidence of prior myocardial infarction underwent a clinically-indicated CMR. We assessed the LA size by direct area measurements in 3 radial planes (DIRECT) and by a standard geometric model (GEO) which calculated LA volume (LAV). LA size was assessed at three time phases during ventricular diastole to determine the conduit and pump functions.
Results: During a median follow up of 19 months, 35 patients experienced MACE including 16 deaths. LA conduit and pump functions by the DIRECT method were highly correlated to the GEO method (r=0.85, p<0.0001 and r=0.83, p<0.0001, respectively). LA conduit function by the DIRECT method was also inversely correlated to LV mass (r=-0.19, p=0.01). Decreased LA conduit and pump functions by the DIRECT method demonstrated strong association with MACE and provided more prognostic information than the GEO method (Table 1⇓).
Conclusions: CMR assessment of LA mechanics without any geometric assumption provides strong prognostic information in hypertensive patients.