Determination of left ventricular mass on cardiac computed tomographic angiography.

RATIONALE AND
OBJECTIVES: Left ventricular hypertrophy (LVH) is associated with an increased risk of cardiac death. The present study evaluates whether using computed tomographic (CT)-derived criteria for normal myocardial mass can improve detection of LVH on CT angiography (CTA).
MATERIALS AND METHODS: A total of 2238 subjects (63 +/- 9 years, 27% female) who underwent CTA were studied. To identify normal limits for CT-derived myocardial mass, we studied normal subjects (those without diabetes, hypertension, congestive heart failure, or coronary artery disease). Left ventricular mass (LVM) was measured manually using two different workstations. The CT criteria of LVH was defined as LVM above the 97th percentile per gender and compared to echocardiographic criteria (110 g/m(2) in women; 124 g/m(2) in men), and specificity and sensitivity of both models to detect LVH were calculated.
RESULTS: The LVM was higher in men than women in normal cohorts (75.5 +/- 14.0 vs. 63.1 +/- 12.8 g/m(2), P = .001 with electron beam CTA and 78.5 +/- 11.9 vs. 65.0 +/- 9.2 g/m(2), P = .001 with 64 multidetector [MD] CT, respectively). The coefficient of variation between electron beam CTA and 64 MDCT for measuring LVM was 3.1%. Comparing the new CTA/64 MDCT criteria of LVH (103.0 g/m(2) in men; 89.0 g/m(2) in women) to the previous echocardiographic criteria of LVH, the specificity in women and men decreased from 100% in both genders by echocardiography to 91.8% and 92.6%, respectively, but the sensitivity increased from 42.0% to 100% and from 41.1% to 100%.
CONCLUSION: This study suggests that CT-measured LVM has low variability and normal values based on CT criteria will potentially increase the early detection of LVH.