Successful treatment of severe combined post- and pre-capillary pulmonary hypertension in a patient with idiopathic restrictive cardiomyopathy

Abstract

Restrictive cardiomyopathy (RCM) is a rare form of cardiomyopathy that is characterized by restrictive ventricular filling. Elevated filling pressure leads to pulmonary hypertension (PH), which often progresses to combined post- and pre-capillary PH (Cpc-PH) with increased diastolic pulmonary vascular pressure gradient (DPG) and pulmonary vascular resistance (PVR) caused by longstanding backward hemodynamic consequences of left heart disease (LHD) leading to morphological changes in the pulmonary vasculature. Patients with high PVR undergoing left ventricular assist device (LVAD) implantation are at increased risk of postoperative right-sided heart failure requiring concomitant implantation of a right ventricular assist device (RVAD). We report a case of RCM with severe Cpc-PH due to extremely elevated DPG and PVR. The patient presented recurrent syncope caused by severe PH. Right heart catheterization (RHC) revealed highly elevated DPG 30 mmHg and PVR 25.3 Wood units (WU) and subsequent significant reduction of right ventricular afterload during vasoreactivity testing with inhaled nitric oxide (NO) to DPG 5 mmHg and PVR 10.5 WU. During the administration of pulmonary vasodilators, pulmonary congestion worsened. Second RHC revealed elevated pulmonary arterial wedge pressure (PAWP) and modest decrease of pulmonary arterial pressure (PAP) 87 mmHg and PVR 9.6 WU. Therefore, an inotropic agent and systemic vasodilator were added for the treatment of left-sided heart failure. Targeting elevated filling pressures with both PAH-specific and heart failure treatment, a further decrease of right ventricular afterload with DPG of 5 mmHg and PVR of 3.8 WU was achieved. In a next step, LVAD was successfully implanted, without need for RVAD, as a bridge to transplantation. This is the first reported case of Cpc-PH that revealed the potential reversibility of extremely elevated DPG and PVR, and suggests the importance of preoperative RHC-guided optimized medical PAH-specific and heart failure treatment before LVAD implantation.

Keywords: combined pre- and post-capillary pulmonary hypertension; diastolic pulmonary vascular pressure gradient; left ventricular assist device; pulmonary vascular resistance; pulmonary vasodilator; restrictive cardiomyopathy.

Fig. 1.

Serial chest radiography images. (a) No pulmonary congestion on admission to an outside institution (February 2015); (b) pulmonary congestion worsened during the titration of pulmonary vasodilators (October 2015); (c) modest pulmonary congestion on admission to our hospital (January 2016); (d) addition of an inotropic agent and systemic vasodilator improved pulmonary congestion (February 2016); (e) after LVAD implantation with pulmonary vasodilators (December 2016).

Fig. 2.

Transthoracic echocardiography on admission to our hospital (a, b; January 2016) and after PAH-specific and heart failure treatment (c; February 2016). (a) Parasternal short-axis views (left, end-diastole; right, end-systole) show a D-shaped left ventricle caused by high pulmonary artery pressure; (b) four-chamber view shows a dilated right ventricle and atrium (left). Color Doppler echocardiography shows severe tricuspid regurgitation. The tricuspid regurgitation pressure gradient was 66 mmHg; (c) parasternal short-axis views (left, end-diastole; right, end-systole) after successful PAH-specific and heart failure treatment show that a D-shaped left ventricle became less clear.