A haemodynamic conundrum: a case report of a patient with concurrent pulmonary arterial hypertension and hypertrophic obstructive cardiomyopathy

BACKGROUND: The co-existence of hypertrophic obstructive cardiomyopathy (HOCM) and pulmonary arterial hypertension (PAH) is extremely rare and poses a management conundrum. This is the first case report in the published literature to describe the diagnosis and management of a patient with both conditions. CASE SUMMARY: A 49-year-old female with a history of HOCM and recently diagnosed scleroderma presented to the clinic with progressive dyspnoea. Transthoracic echocardiogram demonstrated left ventricular outflow tract (LVOT) obstruction at rest, and elevated pulmonary artery (PA) pressure. Cardiac catheterization (CC) demonstrated an LVOT gradient of 150 mmHg, PA pressure of 88/32 mmHg, pulmonary capillary wedge pressure (PCWP) 12 mmHg, pulmonary vascular resistance 14.8 Wu, and a cardiac index of 1.6 L/min/m(2). The differential diagnosis for the dyspnoea included combined pre- and post-capillary pulmonary hypertension from longstanding HOCM vs. scleroderma associated PAH. Tadalafil was added to the patient’s medical regimen of metoprolol but it was stopped because the patient developed pulmonary oedema. Alcohol septal ablation was undertaken with improvement in the LVOT gradient, but only a modest improvement in her dyspnoea. Repeat CC demonstrated worsening PAH. Vasodilatory testing with nitric oxide led to an improvement in the PA pressure with minimal increase of the PCWP. Hence, she was started on treprostinil and macitentan, with significant improvement in her dyspnoea on follow-up. CONCLUSION: In patients with concurrent HOCM and advanced PAH, a multidisciplinary treatment approach is needed to rapidly and safely optimize the background of HOCM in order to permit the use of PAH-specific medications.