Cardiac Changes and Their Reversal Following Curative Surgery in Pheochromocytoma: PheoCard Prospective Cohort Study

Background Pheochromocytoma and paraganglioma (PPGL) are catecholamine producing tumors of chromaffin cell origin, known to cause varied cardiovascular manifestations from hypertension to myocardial infarction. This study sought to objectively evaluate the cardiac changes in PPGL patients and their reversal following curative surgery. Methods The PheoCard study was registered in ClinicalTrials.gov (NCT05082311) and involved 35 consecutive PPGL patients managed as per standard protocol involving alpha blockade followed by curative surgery. They underwent detailed cardiac evaluation using 2D-echocardiography and speckle tracking echocardiography at the time of diagnosis, 7-10 days after alpha blockade, and at 7 days, 3 months, and 6 months after surgical removal. Age- and gender-matched essential hypertensives and healthy individuals (10 in each group) served as two control groups. Results Patients with PPGLs had significantly higher mean blood pressure, left ventricle end-diastolic dimension and volume (LVEDD, LVEDV), left ventricle end-systolic volume (LVESV), septal wall thickness, LV hypertrophy, lower mean LV ejection fraction (LVEF), early diastolic mitral annular velocity (E/A), decreased amplitude of LV longitudinal strain, and increased circumferential strain (p < 0.001) when compared with the control groups at baseline. After alpha blockade, there was marked reduction in the mean LVEDD, LVEDV, LVESV, and normalization of E/A ratio (p < 0.001) in the PPGL patients. Following curative surgery (normalization of fractionated urinary metanephrines at 7-10 days post-operatively), there was early improvement in all echocardiographic parameters and it continued to improve even at 6 months after surgery. There was marked improvement in the global longitudinal strain as seen on serial speckle tracking echocardiography with recovery of most of the segments of LV depicting the reversal of subclinical endocardial dysfunction (p < 0.001). Conclusion PPGL patients despite normal systolic function have subclinical LV diastolic dysfunction which is reversed after curative surgery.