sildenafil-citrate and Cardiomyopathy--Dilated

Cyclic guanosine monophosphate (cGMP) and its primary signaling kinase, protein kinase G, play an important role in counterbalancing stress remodeling in the heart. Growing evidence supports a positive impact on a variety of cardiac disease conditions from the suppression of cGMP hydrolysis. The latter is regulated by members of the phosphodiesterase (PDE) superfamily, of which cGMP-selective PDE5 has been best studied. Inhibitors such as sildenafil and tadalafil ameliorate cardiac pressure and volume overload, ischemic injury, and cardiotoxicity. Clinical trials have begun exploring their potential to benefit dilated cardiomyopathy and heart failure with a preserved ejection fraction. This review discusses recent developments in the field, highlighting basic science and clinical studies.

Topics: Carbolines; Cardiomyopathy, Dilated; Cyclic AMP; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Cyclic Nucleotide Phosphodiesterases, Type 5; Fibrosis; Heart; Heart Failure; Humans; Hypertrophy; Myocardium; Phosphodiesterase 5 Inhibitors; Phosphoric Diester Hydrolases; Piperazines; Purines; Sildenafil Citrate; Sulfones; Tadalafil; Transforming Growth Factor beta; TRPC Cation Channels; Ventricular Remodeling

Cases of sudden death associated with sildenafil citrate use have been reported in men with coronary artery disease. The aim of this study was to investigate the drug's effect on cardiac repolarization and sinus autonomic and vascular control in men with mild chronic heart failure (CHF; New York Heart Association classification II). Changes in these variables could predispose patients to malignant ventricular arrhythmias.. We measured QT dispersion, the QT-RR slope, and the index of QT variability (QTVI) and analyzed spectral power of RR and systolic blood pressure variability in 10 men with dilated cardiomyopathy and in 10 control subjects after administration of a single 50-mg oral dose of sildenafil citrate or placebo at rest (not followed with any attempt at intercourse).. In both groups, oral sildenafil citrate decreased the systolic blood pressure (P <.05) and increased the heart rate (P <.05). In subjects with CHF, it also increased the QT-RR (P <.001) and QTVI (from -0.45 +/- 0.07 to -0.27 +/- 0.07; P <.001), but in controls, it increased the QTVI (from -1.20 +/- 0.08 to -0.78 +/-.014; P <.001). In these subjects and controls, oral sildenafil citrate induced a significant reduction in high frequency, expressed in absolute power (subjects with CHF: from 4.04 +/- 0.14 to 3.43 +/- 0.16 natural logarithm ms2; P <.001; controls: from 5.61 +/- 0.44 to 4.98 +/- 0.32 natural logarithm ms2; P <.05) and in normalized units (P <.05). In subjects with CHF but not in controls, it also significantly increased the low frequency to high frequency ratio (from 1.3 +/- 0.12 to 1.89 +/- 0.16; P <.001) and low frequency expressed in normalized units (P <.05). Sildenafil citrate caused no significant changes in the QT interval or dispersion.. These findings indicate that, in men with heart failure, sildenafil citrate reduces vagal modulation and increases sympathetic modulation, probably through its reflex vasodilatory action. The autonomic system changes induced with sildenafil citrate could alter QT dynamics. Both changes could favor the onset of lethal ventricular arrhythmias. At the dose usually taken for erectile dysfunction, sildenafil citrate has no direct effect on cardiac repolarization (QT interval or dispersion).

Topics: Administration, Oral; Autonomic Nervous System; Blood Pressure; Cardiomyopathy, Dilated; Case-Control Studies; Electrocardiography; Heart Rate; Humans; Male; Middle Aged; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Single-Blind Method; Sulfones; Systole

We report a 3-year-old boy weighing 13.5 kg who presented with intractable cardiac failure resulting from myocarditis and was treated by implantation of a HeartWare (HVAD) device. He was discharged home with the device. His cardiac function subsequently recovered, and the device was decommissioned. We believe this to be the youngest HVAD recipient and the only child to have recovered and had the device decommissioned.

Topics: Anticoagulants; Biopsy; Cardiomyopathy, Dilated; Child, Preschool; Combined Modality Therapy; Heart Failure; Heart-Assist Devices; Humans; Imaging, Three-Dimensional; Male; Milrinone; Myocarditis; Myocardium; Recovery of Function; Sildenafil Citrate; Thrombosis; Tomography, X-Ray Computed; Vasodilator Agents

There has been no established medical therapy to ameliorate pulmonary hypertension (PH) owing to left heart disease (LHD-PH). It has recently been shown that the left ventricular assist device (LVAD) can improve LHD-PH and therefore has the potential to become a major bridge tool for heart transplantation (HTx). However, some patients still have persistent PH even after LVAD treatment. It is essential to demonstrate the reversibility of end-organ dysfunction, including PH, prior to implantable LVAD treatment, especially in Japan, because implantable LVAD treatment is indicated only as bridge to transplantation. Here we report a patient with LHD-PH whose PH was demonstrated to be reversible by the acute pulmonary vasoreactivity test (APVT) with nitrogen monoxide (NO) and the phosphodiesterase-5 inhibitor sildenafil. Both inhaled NO and sildenafil reduced pulmonary vascular resistance, but pulmonary capillary wedge pressure was increased by NO, which was conversely decreased under increased cardiac output by sildenafil. After the patient was listed as an HTx recipient, pulmonary vascular resistance recovered down to an acceptable range with LVAD treatment. Based on these findings, we suggest that the APVT with sildenafil may be a useful and safe tool to predict improvement of PH after LVAD treatment.

Topics: Adult; Cardiomyopathy, Dilated; Heart Failure; Heart Transplantation; Heart-Assist Devices; Humans; Hypertension, Pulmonary; Male; Nitric Oxide; Piperazines; Prosthesis Implantation; Purines; Sildenafil Citrate; Sulfones

Topics: Cardiomyopathy, Dilated; Cyclic Nucleotide Phosphodiesterases, Type 5; Heart Failure; Humans; Myocytes, Cardiac; Phosphodiesterase 5 Inhibitors; Piperazines; Purines; Sildenafil Citrate; Stroke Volume; Sulfones; Ventricular Remodeling

We investigated whether early combined autologous adipose-derived mesenchymal stem cell (ADMSC) and sildenafil therapy offers an additive benefit in preserving heart function in rat dilated cardiomyopathy (DCM).. Adult Lewis rats (n = 8 per group) were divided into group 1 (normal control), group 2 (saline-treated DCM rats), group 3 [2.0 × 106 ADMSC implanted into left ventricular (LV) myocardium of DCM rats], group 4 (DCM rats with sildenafil 30 mg/kg/day, orally), and group 5 (DCM rats with combined ADMSC-sildenafil). Treatment was started 1 week after DCM induction and the rats were sacrificed on day 90.. The results showed that mitochondrial protein expressions of connexin43 and cytochrome-C were lowest in group 2, and lower in groups 3 and 4 than in group 5 (p < 0.002). Conversely, oxidative index was highest in group 2, and also higher in groups 3 and 4 than in group 5 (p < 0.0003). The mRNA expressions of interleukin (IL)-10, Gro/IL-8, endothelial nitric oxide synthase, and Bcl-2 were lowest in group 2, and lower in groups 3 and 4 compared with group 5 (p < 0.0001). The mRNA expressions of matrix metalloproteinase-9, Bax, caspase 3, and stromal-cell derived factor-1α were highest in group 2, and higher in groups 3 and 4 than in group 5 (p < 0.0004). Apoptosis and fibrosis in LV myocardium were most prominent in group 2 and higher in groups 3 and 4 than in group 5, whereas angiogenesis and LV ejection fraction were lowest in group 2 and lower in groups 3 and 4 than in group 5 (p < 0.003).. Early combined ADMSC/sildenafil is superior to either treatment alone in preserving LV function.

Topics: Adipose Tissue; Animals; Apoptosis; Body Weight; Cardiomyopathy, Dilated; Connexin 43; Cytochromes c; Flow Cytometry; Immunohistochemistry; Male; Mesenchymal Stem Cells; Organ Size; Oxidative Stress; Phosphodiesterase Inhibitors; Piperazines; Purines; Rats; Rats, Inbred Lew; Reverse Transcriptase Polymerase Chain Reaction; Sildenafil Citrate; Sulfones; Ultrasonography

Heart transplantation is contraindicated in patients with acute irreversible pulmonary hypertension (PH), but new drugs are opening up therapeutic possibilities. Sildenafil citrate is a nonselective pulmonary vasodilator that is being used in our hospital to treat several patients with PH and which has allowed the inclusion of 1 patient on the waiting list for heart transplantation. A 20-year-old man with Becker muscular dystrophy was diagnosed at the age of 19 years with dilated cardiomyopathy with severe pulmonary artery systolic pressure (PH = 60 mm Hg). A pretransplantation study, including a right hemodynamic analysis with an acute vasodilator test using intravenous epoprostenol, revealed the irreversible character of the PH. Inasmuch as the administration of dobutamine did not achieve an adequate reduction of PH, oral sildenafil was started (25 mg every 12 hours) as salvage therapy. An echocardiogram obtained 2 months after starting sildenafil therapy showed normal right cavities, previously dilated, as well as minimal protosystolic tricuspid regurgitation without PH. A new right hemodynamic study performed after 4 months showed a reduction in pulmonary vascular resistance, from 8 U to 3.5 U Woods. As a result, the patient has now been included on the waiting list for heart transplantation. The promising example of this patient confirms the necessity to carry out controlled trials to establish definitively the indications for the use of sildenafil in patients with irreversible PH.

Topics: Administration, Oral; Adult; Blood Pressure; Cardiac Output; Cardiomyopathy, Dilated; Echocardiography; Heart Rate; Heart Transplantation; Humans; Hypertension, Pulmonary; Male; Patient Selection; Piperazines; Pulmonary Circulation; Purines; Sildenafil Citrate; Sulfones; Vascular Resistance; Vasodilator Agents

Patients with increased pulmonary vascular resistance may experience acute pulmonary hypertension after heart transplantation. Pulmonary vasodilator drugs usually are delivered by the intravenous or the endotracheal route during acute pulmonary hypertensive crisis. Oral pulmonary vasodilators have a potential role in less acutely ill patients with increased pulmonary artery pressure after heart transplantation. We describe the 1st successful post-operative use of oral sildenafil for pulmonary vasodilation in a patient after heart transplantation.

Topics: Administration, Oral; Cardiomyopathy, Dilated; Child, Preschool; Female; Heart Transplantation; Humans; Hypertension, Pulmonary; Piperazines; Purines; Sildenafil Citrate; Sulfones; Vasodilator Agents