Safety of Adenosine for Acute Pulmonary Vasoreactivity Testing in Pulmonary Hypertension

Acute pulmonary vasoreactivity testing (APVT) is performed during right heart catheterization (RHC) in patients with pulmonary arterial hypertension (PAH) to identify those who may benefit from long-term calcium channel blocker (CCB) therapy. Inhaled nitric oxide (iNO) is the most commonly used agent. However, a few other agents such as intravenous (i.v.) epoprostenol or i.v. adenosine can also be used. At present, intravenous prostaglandins and iNO are expensive and not-easily available in most Iranian medical facilities. Indeed intravenous adenosine is less expensive and available in all hospital settings.
We aimed to investigate the safety profile of adenosine in a group of Iranian PAH patients undergoing APVT.
In this prospective study, a total of 57 consecutive patients with PAH who were scheduled to undergo RHC were enrolled. Acute reactivity testing was performed in 56 patients.
Twenty (36%) patients had positive APVT. In all cases, adenosine administration was limited by the occurrence of drug-induced minor side effects including chest pressure or tightness, flushing and dyspnea. The maximal tolerated dose of adenosine was 225 ± 25 µg/kh/min (range 200 - 300 µg/kh/min) in the study population. Only 2 patients developed atrioventricular block at doses of 100 µg/kh/min and 150 µg/kh/min, respectively. Both patients spontaneously converted to sinus rhythm within one minute of discontinuation of adenosine infusion.
Intravenous adenosine can be safely used for APVT in Iran.