Studies show that sildenafil should be avoided in cases of residual pulmonary hypertension and valve diseases

  1. Home
  2. BLOG
  3. Studies show that sildenafil should be avoided in cases of residual pulmonary hypertension and valve diseases

Sildenafil, which treats residual hypertension in patients with heart valve defects, leads to a deterioration in clinical outcomes, including a 2-fold increase in the risk of hospitalization compared to placebo, according to the results of the SIOVAC study published today on the LBCT hotline at the ESC Congress.

“Valve diseases are considered the next cardiac epidemic because of their close association with age and the rapid aging of populations around the world,” said lead researcher Dr. Javier Bermejo, a cardiologist at the Gregorio Maranhon General University Hospital in Madrid, Spain.

“The only established treatment is to repair or replace the valve surgically or percutaneously,” he continued. “However, symptoms often persist for a long time or reappear. Residual pulmonary hypertension is the most important risk factor for death and disability after successful correction of valve lesions.”

Pulmonary hypertension is an increase in blood pressure in the pulmonary artery. In patients with chronic heart valve disease, high pressure in the left half of the heart is transferred back to the pulmonary vessels, which thicken in response. This process may not recover after valve treatment, which leads to persistent pulmonary hypertension.

Sildenafil is an effective vasodilator that has a strong effect on blood flow. Commonly used to treat erectile dysfunction, the drug is also useful for pulmonary hypertension, but clinical trials have shown conflicting results for retrograde pulmonary hypertension. Sildenafil is considered safe and well tolerated, and it is often prescribed to patients with retrograde pulmonary hypertension as an independent symptom.

The SIOVAC2 study tested the potential of sildenafil to improve long-term outcomes in patients with residual pulmonary hypertension after correction of valvular lesions. The study was conducted in 17 public hospitals and coordinated by the Spanish Center for Cardiovascular Research (CIBERCV).

A total of 200 patients were randomized and received sildenafil (40 mg 1 time per day 3 times) or placebo for 6 months. Patients and researchers were blind to the treatment. Before admission, patients were screened for contraindications to taking sildenafil, and catheterization was performed to confirm increased pressure in the pulmonary artery.

The main endpoints were death from all causes, hospitalization for heart failure, deterioration in exercise tolerance (measured by a change in functional class) and deterioration in well-being compared with the start of medication (self-medication).

In contrast to the expected results, clinical outcomes were worse in the sildenafil group compared to placebo. After 6 months, 33 (33%) patients taking sildenafil and 14 (15%) patients taking placebo had a worse overall clinical assessment than at the beginning of the study (there was no chance of improvement).

Dr. Bermejo said, “We are very pleased to announce the launch of this new technology.” Compared with patients taking placebo, patients taking sildenafil were more than 2 times more likely to have a worse clinical outcome, which is determined by their combined clinical indicators. We have not been able to identify a specific group of patients to whom sildenafil could potentially benefit.”

Patients taking sildenafil were more likely to be hospitalized due to decompensation of heart failure. In fact, the overall risk of hospitalization was 2 times higher than in patients taking the drug. Three patients taking sildenafil and two patients taking placebo died during the study (p=0.63). Serious clinical events (death from heart failure or re-hospitalization) occurred earlier and more often in the group taking sildenafil (risk ratio 2.0; 95% CI 1.0〜4.0; p=0.044).

“We were surprised that decompensation requiring hospitalization was more common in patients taking sildenafil,” Dr. Bermejo said. “This is the first clinical study dedicated to this complication,” he continued. “In patients with residual pulmonary hypertension, after successful correction of a heart valve defect, we found that 6 months of treatment with sildenafil resulted in worse clinical results than placebo.”

Dr. Bermejo concluded that “long-term use of sildenafil for the treatment of residual pulmonary hypertension in patients with heart valve defects should be avoided.” The high incidence of complications during the study highlights the need for further research to prevent and treat this complication in patients with heart valve disease.”.

Read also