Ventricular-Vascular Coupling in Marfan and Non-Marfan Aortopathies

Background-Marfan syndrome (MFS) and familial non-syndromal thoracic aortic aneurysm and dissection (ns-TAAD) are genetic aortopathies causing aortic dilatation with increased aortic stiffness. Left ventricular (LV) contractility and ventricular-vascular coupling index (VVI) were compared between MFS and ns-TAAD and determinants of VVI were investigated. Methods and Results-Patients with MFS (M 57, F 47) and ns-TAAD (M 72, F 39) were studied by echocardiography and compared with controls (M 77, F 71). Aortic geometry, hemodynamics, LV work, LV contractility (end-systolic elastance [ E-es]), and VVI were documented. Aortic sinuses were equally dilated in MFS (19.7 +/- 2.4) and ns-TAAD (19.8 +/- 1.8) compared to controls (16.2 +/- 1.4 mm.m(-2), P<0.001). Aortic stiffness index was increased in MFS (9.7 +/- 5.1) and ns-TAAD (10.8 +/- 4.7) versus controls (5.4 +/- 2.0, P<0.01); LV stroke work was unchanged in MFS (436 +/- 74) compared to controls (435 +/- 60) but increased in ns-TAAD (492 +/- 109 mJ.m(-2) P<0.01). The LV Ees was reduced in MFS (1.32 +/- 0.19) compared to controls (1.65 +/- 0.29 mm Hg.mL(-1), P<0.01) but increased in ns-TAAD (1.83 +/- 0.30, P<0.01) and VVI was abnormal in MFS (0.71 +/- 0.11) compared to controls (0.62 +/- 0.07, P<0.01) and ns-TAAD (0.62 +/- 0.09). Treatment with beta-blockers was associated with partial normalization of VVI in MFS. A VVI >= 0.8 was associated with increased risk of death and heart failure in MFS. Conclusions-Left ventricular contractility and ventricular-vascular coupling are abnormal in MFS but preserved in ns-TAAD, and are independent of aortic stiffness, consistent with intrinsic impairment of myocardial contractility in MFS.