Aim: To compare cardiovascular magnetic resonance (CMR)-derived right ventricular fractional shortening (RVFS), tricuspid annular plane systolic excursion with a reference point within the right ventricular apex (TAPSEin) and with one outside the ventricle (TAPSEout) with the standard volumetric approach in patients with hypertrophic cardiomyopathy (HCM).
Methods and results: 105 patients with HCM and 20 healthy subjects underwent CMR. In patients with HCM, TAPSEin (r = 0.31, p = 0.001) and RVFS (r = 0.35, p = 0.0002) revealed a significant but weak correlation with right ventricular ejection fraction (RVEF), whereas TAPSEout (r = 0.57, p < 0.0001) showed a moderate correlation with RVEF. The ability to predict RVEF < 45 % in HCM patients was best for TAPSEout. In patients with hypertrophic obstructive cardiomyopathy (HOCM), RVEF showed a significant but weak correlation with TAPSEout (r = 0.36, p = 0.02) and no correlation with TAPSEin (r = 0.05, p = 0.07) and RVFS (r = 0.02, p = 0.2). In patients with hypertrophic non-obstructive cardiomyopathy (HNCM), there was a moderate correlation between RVEF and TAPSEout (r = 0.57, p < 0.0001) and a weak correlation with TAPSEin (r = 0.39, p = 0.001) and RVFS (r = 0.38, p = 0.002). In the 20 healthy controls, there was a strong correlation between RVEF and all semi-quantitative measurements.
Conclusion: CMR-derived TAPSEin is not suitable to determine right ventricular function in HCM patients. TAPSEout showed a good correlation with RVEF in HNCM patients but only a weak correlation in HOCM patients. TAPSEout might be used for screening but the detection of subtle changes in RV function requires the 3D volumetric approach.