Evaluation of angiotensin converting enzyme activity and hemodynamic effects of angiotensin converting enzyme inhibitor in bilharzial cor pulmonale

ABSTRACT

Serum angiotensin converting enzyme [ACE] activity as well as systemic and pulmonary hemodynamic parameters were evaluated in 15 patients with bilharzial cor pulmonale through right sided cardiac catheter before and 60 minutes after oral administration of 50 mg of angiotensin converting enzyme inhibitor [ACEI] captopril. Following long term treatment with ACEI at a daily dose of 50 mg for 3 weeks, the same parameters were re-evaluated. Angiotensin enzyme activity was found to be significantly high [P <0.01] relative to control before initial dose treatment and demonstrated significant reduction [P <0.01] in activity following ACEI treatment. This reduction in activity coincided with the improvement in hemodynamics. Following 60 minutes of ACEI administration, significant reduction [P <0.01] in mean pulmonary artery pressure [MPAP], pulmonary capillary wedge pressure PCWD [P <0.01], pulmonary vascular resistance PVR [P <0.01] and right ventricular stroke work index RVSWI [P <0.01] were noted. Significant decreases in mean systemic blood pressure SBP [P <0.01], systemic vascular resistance SVR [P <0.01] and left ventricular stroke work index LVSWI [P <0.01] were also recorded. Cardiac index CI showed insignificant change. Hemodynamic effects of long term treatment of ACEI at daily dose of 50 mg revealed less but still significant changes similar to the acute hemodynamic effects. These results suggested that ACE plays a role in pulmonary hypertension in patients with bilharzial cor pulmonale and hence ACEI may be beneficial in reducing its severity