Combined administration of intravenous dipyridamole and inhaled nitric oxide to assess reversibility of pulmonary arterial hypertension in potential cardiac transplant recipients.
ABSTRACT Irreversible, severe pulmonary hypertension (PH) can produce right heart failure and early mortality after cardiac transplantation. We hypothesized that dipyridamole, an inhibitor of Type 5 phosphodiesterase, would augment the ability of inhaled nitric oxide (NO) to identify reversibility of PH.
In 9 patients with congestive heart failure (CHF) and severe PH who were breathing 100% oxygen during right heart catheterization, we administered inhaled NO (80 ppm) alone and in combination with intravenous dipyridamole (0.2-mg/kg bolus, with an infusion of 0.0375 mg/kg/min).
Compared with breathing oxygen alone, NO inhalation decreased pulmonary artery pressure and pulmonary vascular resistance (PVR) (by 10 +/- 4% and 26 +/- 12% [mean +/- SEM], respectively; both p < 0.05). The combination of NO and dipyridamole reduced PVR (43 +/- 7%; p < 0.05) to a greater extent than did administration of NO alone, and increased the duration of pulmonary vasodilation produced by NO inhalation. Combined administration of inhaled NO and intravenous dipyridamole increased cardiac index (by 23 +/- 10%) and reduced SVR (by 19 +/- 6%, both p < 0.05) without changing systemic arterial pressure. NO inhalation reduced PVR to <200 dyne x s/cm5 in 3 of 7 patients who had a PVR of >200 dyne x s/cm5 when breathing oxygen alone, whereas the combination of NO and dipyridamole decreased PVR to <200 dyne.s/cm(5) in 2 additional patients.
Intravenous dipyridamole augments and prolongs the pulmonary vasodilator effects of inhaled NO in CHF patients with severe PH and, when administered in combination with NO inhalation, can identify PH reversibility in potential cardiac transplant recipients in whom a pulmonary vasodilator response to inhalation of NO alone is not observed.
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ABSTRACT: Una gran variedad de cardiopatías congénitas o adquiridas evolucionan con hipertensión arterial pulmonar. En otras ocasiones esta condición se presenta en el período postoperatorio inmediato de cirugía cardíaca donde puede dar lugar a complicaciones hemodinámicas que requieren del manejo juicioso de distintos recursos en el contexto del tratamiento integral del paciente en la terapia intensiva postquirúrgica. En los últimos años se han logrado algunos avances en el conocimiento de la fisiopatología de esta complicación y por ello ha sido posible implementar algunas estrategias de manejo con fundamentos científicos más sólidos. En el presente trabajo se revisan dichos conceptos y se ofrece un panorama general del tratamiento actual de esta condición clínica en el postoperatorio de cirugía cardíaca.Archivos de cardiología de México 06/2006; 76:76-80.
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ABSTRACT: Multiple drugs are used for reversibility testing of pulmonary hypertension (PH) in advanced heart failure (HF), especially in the process of heart transplant evaluation. Effects of these drugs were never systematically compared. The aim of this meta-analysis was to compare hemodynamic effects of different drugs. We identified 20 prospective studies reporting hemodynamic variables before and after acute pharmacologic testing for PH reversibility in patients with advanced HF. The data from individual studies were grouped by an outcome measure and analyzed. A mixed model meta-analysis was performed using SAS to give weighted mean effect of pre- and post-test change and inverse variance. The mean effects were weighted by the published sample size. Prostacyclin, inhaled or intravenous, and prostaglandin E1 (PGE1) had the most potent effect on pulmonary vascular resistance (PVR). Sodium nitroprusside and nitroglycerin decreased pulmonary capillary wedge pressure (PCWP), and mean pulmonary arterial pressure (MPAP) better than other drugs. Sildenafil provided overall good hemodynamic outcomes but was not the strongest drug with regard to any particular outcome. PCWP, MPAP, and systolic pulmonary arterial pressure respond better to nitroglycerin and sodium nitroprusside than to other drugs in the setting of reversibility testing. Prostacyclin and PGE1 are superior to other drugs in their acute effects on PVR.Pulmonary circulation. 04/2013; 3(2):406-13.
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ABSTRACT: To evaluate the vasoconstrictor component of PH in CHF by investigating the hemodynamic response to inhaled nitric oxide (iNO) and to determine whether this response was influenced by the phosphodiesterase 5 gene (PDE5) G(1142)T polymorphism. CHF patients underwent right heart catheterization at rest and after 20 ppm of iNO and plasma cGMP and PDE5 G(1142)T polymorphism determinations. Of the 72 included CHF patients (mean age, 53±1 years; mean left ventricular ejection fraction, 29±1%; and mean pulmonary artery pressure, 25.5±1.3 mmHg), 54% had ischemic heart disease. Proportions of patients with the TT, GT, and GG genotypes were 39%, 42% and 19% respectively. Baseline hemodynamic characteristics were not significantly different across PDE5 genotype groups, although pulmonary capillary wedge pressure (PCWP) tended to be lower in the TT group (P=0.09). Baseline plasma cGMP levels were significantly lower in the TT than in the GG and GT patients. With iNO, PVR diminished in TT (-33%) but not GG (-1.6%) or GT (0%) patients (P=0.002); and PCWP increased more in TT than in GT (P<0.05) or GG (P<0.003) patients. The PDE5 G(-1142) polymorphism is therefore a major contributor to the iNO-induced PVR decrease in CHF.Pulmonary circulation. 07/2011; 1(3):377-82.