Acute vasodilator response to vardenafil and clinical outcome in patients with pulmonary hypertension.

PURPOSE: Acute vasodilator testing is recommended in patients with pulmonary arterial hypertension to identify individuals who may benefit from long-term treatment with oral calcium channel blockers. The aim of this study was to investigate the use of vardenafil in acute vasoreactivity testing compared to adenosine. METHODS: A total of 20 patients eligible for right heart catheterisation were enrolled. Acute vasoreactivity testing was carried out with intravenous (iv) adenosine (n = 18) followed by oral vardenafil (n = 20). Haemodynamic responses were recorded at baseline and after 60 min (vardenafil). Responders were defined according to consensus guideline criteria. RESULTS: Both vardenafil and adenosine significantly decreased mean pulmonary arterial pressure (mPAP, p < 0.001 and p = 0.026, respectively) and pulmonary vascular resistance (p < 0.001 and p > 0.001, respectively), and significantly increased cardiac output (p = 0.001 and p = 0.005, respectively). Vardenafil reduced mPAP more than adenosine (p = 0.044), while adenosine resulted in higher responses of cardiac index (p = 0.009) and pulmonary arterial oxygen saturation (p = 0.042). Acute adverse reactions were common with adenosine, while no side effects were observed after a single oral dose vardenafil. Vardenafil identified five responders (out of 20), while adenosine identified three responders (out of 18). During a 7-year follow-up, vardenafil responders had significantly lower NT-proBNP levels compared to non-responders. CONCLUSIONS: Vardenafil may be safely used for acute vasoreactivity testing in patients with PH. A single oral dose of vardenafil is better tolerated than iv adenosine and may identify additional responders who could benefit from long-term vasodilator treatment.

Changes in plasma levels of asymmetric dimethylarginine, symmetric dimethylarginine, and arginine after a single dose of vardenafil in patients with pulmonary hypertension.

OBJECTIVE: We investigated whether vardenafil, a phosphodiesterase-5 inhibitor, alters plasma levels of asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and arginine. PATIENTS AND METHODS: ADMA, SDMA, and arginine were measured (0-540 min) in 12 patients with pulmonary hypertension after a single oral dose of vardenafil. Invasive hemodynamic data were collected at baseline and after 60 min. RESULTS: A reduction in ADMA was observed at 30 and 45 min with a median change of -11.1% (P=0.021) and -12.5% (P=0.002). SDMA decreased with a median -5.3% change (P=0.032) at 45 min. An increase in arginine, median 40.3% (P=0.002), 45.0% (P=0.010), and 77.1% (P=0.008) was observed at 120, 300, and 540 min respectively. An increase in the arginine/ADMA ratio, median 11.7% (P=0.012), 32.5% (P=0.003), 26.5% (P=0.021), 33% (P=0.007), 48.5% (P=0.007), and 63.1% (P=0.008) was observed at 15, 45, 60, 120, 300, and 540 min respectively. There was a positive correlation between vardenafil exposure and the percent change in the arginine/ADMA ratio from baseline to 540 min (r=0.80; P=0.01). A correlation between baseline mean right atrial pressure (mRAP) and baseline ADMA (r=0.65; P=0.023), and baseline SDMA (r=0.61; P=0.035) was observed. A correlation between the baseline arginine/ADMA ratio and baseline cardiac output (CO) (r=0.59; P=0.045) and baseline cardiac index (CI) (r=0.61; P=0.036) was observed. Baseline arginine/ADMA ratio correlated with baseline mRAP (r=-0.79; P=0.002). A correlation between change (0-60 min) in CI and change in arginine (r=0.77; P=0.003) as well as change in the arginine/ADMA ratio (r=0.61; P=0.037) was observed. CONCLUSIONS: Vardenafil induced changes in ADMA, SDMA, arginine, and the arginine/ADMA ratio in patients with PH. An increase in arginine and the arginine/ADMA ratio was associated with improvement in CI.

Acute haemodynamic response in relation to plasma vardenafil concentrations in patients with pulmonary hypertension.

AIMS: To evaluate the acute haemodynamic effects of a single oral dose of vardenafil and to study the drug concentration in relation to haemodynamic effects in patients with pulmonary hypertension (PH). METHODS: Sixteen patients with PH (aged 29-85\ years), received one single oral dose of vardenafil (5, 10 or 20 mg). The haemodynamic effect was assessed over a 60 min period. Vardenafil plasma concentrations were measured after 15, 30, 45 and 60 min using liquid chromatography-tandem mass spectrometry. RESULTS: At 60 min a reduction in mPAP with a median % decrease of -20.3% (range -48.3 to 3.0; P < 0.001) and an increase in cardiac output and the cardiac index with a median % change of 10.6% (range -25.0 to 88.1; P = 0.015) and 12.1% (range -24.0 to 94.4; P = 0.01) respectively was observed. The pulmonary vascular resistance (PVR) was reduced with a median % decrease of -28.9% (range -61.5 to -5.9; P < 0.001), and pulmonary selectivity was reflected by a median percent reduction of -16.9% (range -49.0 to 16.5; P = 0.002; n = 14) in the PVR/systemic vascular resistance ratio. There was a correlation between the plasma concentrations of vardenafil and change in mPAP (r = -0.579, P = 0.019) and between vardenafil concentrations and change in PVR (r = -0.662, P = 0.005). CONCLUSIONS: Vardenafil causes rapid changes in cardiopulmonary haemodynamics and there is a correlation between plasma vardenafil drug concentration and the acute changes in mPAP as well as PVR in patients with PH.