Effect of preoperative oral sildenafil on severe pulmonary artery hypertension in patients undergoing mitral valve replacement

A Network Meta-Analysis of Vasodilator Therapies in Pulmonary Hypertension Patients Undergoing Mitral Valve Replacement Surgery: Insights for Optimizing Hemodynamics

BACKGROUND AND OBJECTIVE

Pulmonary hypertension (PH) is a progressive hemodynamic condition associated with significant morbidity and mortality, especially in patients undergoing cardiac surgery. Therefore, the objective of this network meta-analysis (NMA) is to compare the efficacy of various pulmonary vasodilators in perioperative control of PH among patients undergoing mitral valve replacement surgery (MVRS), aiming to address the existing knowledge gap and improve perioperative outcomes.

METHODS

Electronic databases including PubMed, Cochrane Central Registry of Controlled Trials, Scopus, Embase, and Web of Science (WOS) from inception to 17 September 2024. Only randomized controlled trials (RCTs) evaluating vasodilators in PH patients undergoing MVRS were included. We used netmeta package in RStudio to analyze the outcome data with their corresponding mean difference (MD) and confidence intervals (CI).

RESULTS

Seventeen RCTs including 862 patients were analyzed. Prostacyclin, nitric oxide (NO), and sodium nitroprusside (SN) significantly reduced mean pulmonary arterial pressure with effect sizes [MD, 95% confidence interval (CI)] of (11.77, - 18.78; - 4.76; - 8.3, - 15.9; - 0.6; - 11.02, - 20.1; - 3.8, respectively). While no treatment showed significant efficacy on pulmonary capillary wedge pressure, systolic pulmonary arterial pressure, or heart rate, nitroglycerin, NO, and prostacyclin, showed significant increases in cardiac index with effect sizes (MD, 95% CI) of (1, 0.3; 1.7; 1.2 0.8; 1.6; 1.2 0.8; 1.6, respectively). Additionally, NO, prostacyclin, SN, and nitroglycerin demonstrated significant reductions in systemic vascular resistance (SVR), with effect sizes of. (- 0.54, - 0.82; - 0.26, - 0.37, - 0.65; - 0.09; - 0.47, - 0.77; - 0.16; - 0.14, - 0.24; - 0.03, respectively).

CONCLUSIONS

This NMA highlights prostacyclin, nitroglycerin, NO, and SN as consistently effective in improving hemodynamics for patients with PH undergoing MVRS, and provides valuable insights for surgeons to choose the suitable vasodilator for these surgeries. However, limitations and the need for further RCTs are acknowledged.

Pulmonary Vasodilator and Inodilator Drugs in Cardiac Surgery: A Systematic Review With Bayesian Network Meta-Analysis

OBJECTIVE

The authors performed a systematic review to evaluate the effect of pharmacologic therapy on pulmonary hypertension in the perioperative setting of elective cardiac surgery (PROSPERO CRD42023321041).

DESIGN

Systematic review of randomized controlled trials with a Bayesian network meta-analysis.

SETTING

The authors searched biomedical databases for randomized controlled trials on the perioperative use of inodilators and pulmonary vasodilators in adult cardiac surgery, with in-hospital mortality as the primary outcome and duration of ventilation, length of stay in the intensive care unit, stage 3 acute kidney injury, cardiogenic shock requiring mechanical support, and change in mean pulmonary artery pressure as secondary outcomes.

PARTICIPANTS

Twenty-eight studies randomizing 1,879 patients were included.

INTERVENTIONS

Catecholamines and noncatecholamine inodilators, arterial pulmonary vasodilators, vasodilators, or their combination were considered eligible interventions compared with placebo or standard care.

MEASUREMENTS AND MAIN RESULTS

Ten studies reported in-hospital mortality and assigned 855 patients to 12 interventions. Only inhaled prostacyclin use was supported by a statistically discernible improvement in mortality, with a number-needed-to-treat estimate of at least 3.3, but a wide credible interval (relative risk 1.26 × 10-17 - 0.7). Inhaled prostacyclin and nitric oxide were associated with a reduction in intensive care unit stay, and none of the included interventions reached a statistically evident difference compared to usual care or placebo in the other secondary clinical outcomes.

CONCLUSIONS

Inhaled prostacyclin was the only pharmacologic intervention whose use is supported by a statistically discernible improvement in mortality in the perioperative cardiac surgery setting as treatment of pulmonary hypertension. However, available evidence has significant limitations, mainly the low number of events and imprecision.

Safety and Efficacy of Sildenafil for Group 2 Pulmonary Hypertension in Left Heart Failure

Pulmonary hypertension (PH) is a multifactorial, progressive disease with poor outcomes. Group 2 PH is defined by pulmonary vascular disease with elevated pulmonary capillary wedge pressure including both left-sided obstructive lesions and diastolic heart failure (HF). Sildenafil was historically discouraged in this population as pulmonary vasodilation can lead to pulmonary edema. However, evidence suggests that sildenafil can help to treat the precapillary component of PH. This is a single center, retrospective pilot study of pediatric PH patients with left-sided HF who were treated with sildenafil for ≥ 4 weeks. HF patients without mechanical support (HF group) and HF patients with a left ventricular assist device (HF-VAD) were analyzed. The exploratory analysis described the safety and side effects of the drug. Echocardiographic parameters were compared before and after sildenafil treatment in a paired analysis. The changes in medical therapy during treatment, mechanical support, and mortality was reported; 19/22 patients tolerated sildenafil. Pulmonary edema in two patients resolved upon discontinuation of sildenafil. In the HF group, both the right atrial volume and right ventricular diastolic area decreased, and the tricuspid regurgitation (TR) S/D ratio decreased after therapy (p = 0.02). Across both the groups, four patients weaned off milrinone and seven weaned off inhaled nitric oxide. Of the thirteen HF patients, four received a transplant, and all of the nine HF-VAD patients received a transplant. Sildenafil can be safely used in carefully selected patients with HF and mixed pre/postcapillary PH with judicious titration and inpatient surveillance, with patients showing improvements in echocardiographic parameters.

Safety of Phosphodiesterase-5 Inhibitors in Valvular Heart Disease

ABSTRACT

Erectile dysfunction is a common entity in clinical practice. Primary erectile dysfunction, not related to vasculopathy or psychiatric disorder, can be readily treated with phosphodiesterase inhibitors. These drugs have many physiologic effects that can alter a patient's hemodynamic profile considerably, especially in the presence of concomitant structural heart disease, specifically valvular heart disease. Although some contraindications to the use of PDE5 inhibitors in patients with cardiovascular disease are defined, the effect of these drugs in the presence of valvular heart disease is not well documented. The purpose of this review is to analyze the data regarding the safety of PDE5 inhibitors in patients with valvular heart disease.

PDE5 inhibition improves cardiac morphology and function in SHR by reducing NHE1 activity: Repurposing Sildenafil for the treatment of hypertensive cardiac hypertrophy

Previously, we have shown that an increased cGMP-activated protein Kinase (PKG) activity after phosphodiesterase 5 (PDE5) inhibition by Sildenafil (SIL), leads to myocardial Na+/H+ exchanger (NHE1) inhibition preserving its basal homeostatic function. Since NHE1 is hyperactive in the hypertrophied myocardium of spontaneous hypertensive rats (SHR), while its inhibition was shown to prevent and revert this pathology, the current study was aimed to evaluate the potential antihypertrophic effect of SIL on adult SHR myocardium. We initially tested the inhibitory capability of SIL on NHE1 in isolated cardiomyocytes of SHR by comparing H+ efflux during the recovery from an acid load. After confirmed that effect, eight-month-old SHR were chronically treated for one month with SIL through drinking water. Compared to their littermate controls, SIL-treated rats presented a decreased NHE1 activity, which correlated with a reduction in its phosphorylation level assigned to activation of a PKG-p38 MAP kinase-PP2A signaling pathway. Moreover, treated animals showed a decreased oxidative stress that appears to be a consequence of a decreased mitochondrial NHE1 phosphorylation. Treated SHR showed a significant reduction in the pro-hypertrophic phosphatase calcineurin, despite slight tendency to decrease hypertrophy was detected. When SIL treatment was prolonged to three months, a significant decrease in myocardial hypertrophy and interstitial fibrosis that correlated with a lower myocardial stiffness was observed. In conclusion, the current study provides evidence concerning the ability of SIL to revert established cardiac hypertrophy in SHR, a clinically relevant animal model that resembles human essential hypertension.

Intravenous sildenafil citrate and post-cardiac surgery acute kidney injury: a double-blind, randomised, placebo-controlled trial

BACKGROUND

This study assessed whether i.v. sildenafil citrate prevented acute kidney injury in at-risk patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

In a double-blind RCT, adults at increased risk of acute kidney injury undergoing cardiac surgery in a single UK tertiary centre were randomised to receive sildenafil citrate 12.5 mg kg^-1 i.v. over 150 min or dextrose 5% at the commencement of surgery. The primary outcome was serum creatinine measured at six post-randomisation time points. The primary analysis used a linear mixed-effects model adjusted for the stratification variables, baseline estimated glomerular filtration rate, and surgical procedure. Secondary outcomes considered clinical events and potential disease mechanisms. Effect estimates were expressed as mean differences (MDs) or odds ratios with 95% confidence intervals.

RESULTS

The analysis population comprised eligible randomised patients that underwent valve surgery or combined coronary artery bypass graft and valve surgery, with cardiopulmonary bypass, between May 2015 and June 2018. There were 60 subjects in the sildenafil group and 69 in the placebo control group. The difference between groups in creatinine concentration was not statistically significant (MD: 0.88 μmol L^-1 [-5.82, 7.59]). There was a statistically significant increase in multiple organ dysfunction scores in the sildenafil group (MD: 0.54 [0.02, 1.07]; P=0.044). Secondary outcomes, and biomarkers of kidney injury, endothelial function, and inflammatory cell activation, were not significantly different between the groups.

CONCLUSIONS

These results do not support the use of i.v. sildenafil citrate for kidney protection in adult cardiac surgery.

CLINICAL TRIAL REGISTRATION

ISRCTN18386427.

Pre-Operative Sildenafil for Patients With Pulmonary Hypertension Undergoing Mitral Valve Surgery: A Systematic Review and Meta-Analysis

Background

Pulmonary hypertension is a usual complication of long-standing mitral valve disease. Perioperative pulmonary hypertension is a risk factor for right ventricular failure and is an important cause of morbidity and mortality in patients with pulmonary hypertension undergoing mitral valve surgery. Phosphodiesterase-5 inhibitors particularly sildenafil citrate have proven clinical benefit for pulmonary arterial hypertension but have shown discordant results in group 2 pulmonary hypertension patients. We sought to determine the effect of pre-operative sildenafil on the intra-operative hemodynamic parameters of these patients.

Methods

Studies were included if they satisfied the following criteria: 1) Randomized controlled trials; 2) Adult patients with pulmonary hypertension scheduled for elective mitral valve surgery; and 3) Reported data on changes in pre-, intra-, and post-operative hemodynamic parameters. Using PUBMED, Clinical Key, Science Direct, and Cochrane databases, a search for eligible studies was conducted from September 1 to December 31, 2018. The quality of each study was evaluated using the Cochrane Risk of Bias Tool. The primary outcome of interest is on the effect of pre-operative sildenafil on the improvement of intra-operative hemodynamic parameters such as systolic pulmonary artery pressure (sPAP), mean pulmonary arterial pressure, mean arterial pressure, pulmonary and systemic vascular resistances. We also investigated its effect on the post-operative mortality, length of cardiopulmonary bypass time, ventilation time, and inotrope support requirement. Review Manager 5.3 was utilized to perform analysis of random effects for continuous outcomes.

Results

We identified three studies involving 153 patients with pulmonary hypertension undergoing mitral valve surgery, showing that among those who received pre-operative sildenafil there is a significant decrease in intra-operative systolic pulmonary arterial pressure (mean difference -11.19 (95% confidence interval (CI), -20.23 to -2.15), P < 0.05) and post-operative sPAP (mean difference -13.67 (95% CI, - 19.56 to - 7.78), P < 0.05) without significantly affecting the mean arterial pressure (mean difference 1.94 (95% CI, -5.49 to 9.37), P < 0.05). The systemic and pulmonary vascular resistances were not affected as well.

Conclusions

Administration of pre-operative sildenafil to patients with pulmonary hypertension undergoing mitral valve surgery decreases intra-operative and post-operative systolic pulmonary arterial pressure without significantly affecting other systemic hemodynamic parameters.

Proconvulsant effects of sildenafil citrate on pilocarpine-induced seizures: Involvement of cholinergic, nitrergic and pro-oxidant mechanisms

Sildenafil is a phosphodiesterase 5 inhibitor used for the treatment of erectile dysfunction and pulmonary hypertension. Proconvulsant effect is a serious adverse event associated with sildenafil use. Here, we investigated the possible proconvulsant effects of sildenafil in pilocarpine (PILO)-induced seizures model, which mimics some aspects of temporal lobe epilepsy. We also evaluated sildenafil's effects on hippocampal markers related to PILO-induced seizure, for instance, acetylcholinesterase (AChE) activity, oxidative stress and nitric oxide (NO) markers, namely nitrite, inducible NO synthase (iNOS) and neuronal NOS (nNOS). The influences of muscarinic receptors blockade on sildenafil proconvulsant effects and brain nitrite levels were also evaluated. Male mice were submitted to single or repeated (7 days) sildenafil administration (2.5, 5, 10 and 20 mg/kg). Thirty minutes later, PILO was injected and mice were further evaluated for 1 h for seizure activity. Sildenafil induced a dose- and time-progressive proconvulsant effect in PILO-induced seizures. Sildenafil also potentiated the inhibitory effect of PILO in AChE activity and induced a further increase in nitrite levels and pro-oxidative markers, mainly in the hippocampus. Repeated sildenafil treatment also increased the hippocampal expression of iNOS and nNOS isoforms, while the blockade of muscarinic receptors attenuated both sildenafil-induced proconvulsant effect and brain nitrite changes. Our data firstly demonstrated the proconvulsant effect of sildenafil in PILO-model of seizures. This effect seems to be related to an increased cholinergic-nitrergic tone and pro-oxidative brain changes. Also, our findings advert to caution in using sildenafil for patients suffering from neurological conditions that reduces seizure threshold, such as epilepsy.

Sildenafil for Pulmonary Hypertension in the Early Postoperative Period After Mitral Valve Surgery

OBJECTIVES

The phosphodiesterase-5 inhibitor sildenafil was developed for the treatment of pulmonary hypertension. The authors investigated the efficacy and safety of sildenafil in the early postoperative period after mitral valve surgery in patients with pulmonary hypertension.

DESIGN

A double-blind, placebo-controlled randomized trial was performed.

SETTING

The trial was performed in a single tertiary referral center.

PARTICIPANTS

Fifty consecutive patients who experienced pulmonary hypertension and underwent mitral valve surgery.

INTERVENTIONS

Patients were randomly assigned to the following 2 groups: 25 patients received 20 mg sildenafil every 8 hours, and the remaining 25 patients received placebo during the same period. Hemodynamic parameters were studied by using a pulmonary artery catheter at baseline and every 6 hours up to 36 hours.

RESULTS

Patients who received sildenafil showed a decrease in mean pulmonary pressure, from 32 ± 7 mmHg at baseline to 26 ± 3 mmHg after 36 hours, whereas no change was seen in patients who received placebo (mean pulmonary pressure 34 ± 6 mmHg at baseline and 35 ± 5 mmHg after 36 h) (p < 0.001). No significant changes in systemic hemodynamic and oxygenation were observed. Patients who received sildenafil compared with those who received placebo had a median mechanical lung ventilation time of 16 (10-31) hours versus 19 (13-41) hours (p = 0.431), intensive care unit stay of 74 (44-106) hours versus 91 (66-141) hours (p = 0.410), and a total hospitalization stay of 7 (5-10) days versus 11 (7-15) days (p = 0.009).

CONCLUSIONS

The immediate postoperative administration of sildenafil after mitral valve surgery is safe. Sildenafil demonstrates a favorable decreasing effect on pulmonary vascular pressure without systemic hypotension and ventilation-perfusion mismatch.

Postoperative Right Ventricular Failure in Cardiac Surgery

Two cases of patients that developed right ventricular failure (RVF) after cardiac valve surgery are presented with a narrative revision of the literature. RVF involves a great challenge due to the severity of this condition; it has a low incidence among non-congenital cardiac surgery patients, is more likely associated with cardiovascular and pulmonary complications related to cardiopulmonary bypass (CPB), and is a cause of acute graft failure and of a higher early mortality in cardiac transplant. The morphologic and hemodynamic characteristics of the right ventricle and some specific factors that breed pulmonary hypertension after cardiac surgery are in favor of the onset of RVF. Due to the possibility of complications after cardiac valve repair or replacement, measures as appropriate hemodynamic monitoring, to manage oxygenation, ventilation, sedation, acid base equilibrium and perfusion goals are a requirement, as well as a normal circulating volume, and the prevention of a disproportionate rise in the afterload, to preserve the free wall of the right ventricle (RV) and the septum's contribution to the right ventricular global function and geometry. If there is no response to these basic measures, the use of advanced therapy with inotropics, intravenous or inhaled pulmonary vasodilation agents is recommended; the use of mechanical ventricular assistance stands as a last resource.