Ventricular-Vascular Coupling in Marfan and Non-Marfan Aortopathies

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.

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 E_es 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 β-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.

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.