A retrospective database analysis found that the number of pulmonary arterial hypertension (PAH) hospitalizations per year decreased 58 percent from 2001 through 2012, although the mean hospital charge per admission increased 2.7-fold during that time period.

In addition, the in-hospital mortality rate remained consistent, but the length of hospitalization increased.

Lead researcher Vidhu Anand, MD, of the University of Minnesota School of Medicine in Minneapolis, and colleagues published their results online in JAMA Cardiology on Nov. 16.

“The 58 percent decrease in number of admissions during the study period likely reflects an overall improvement in the out- patient care of these patients and likely favorable disease course with the availability of PAH-specific vasodilator therapies,” the researchers wrote.

The researchers mentioned that the estimated prevalence of PAH was 10 to 50 cases per one million people and that the one-year mortality rates were 10 percent to 15 percent.

For this study, the researchers searched the National Inpatient Sample database, which contains data from 1,000 hospitals and approximately eight million hospitalizations per year from 46 states. They identified adults who had PAH as their principal discharge diagnosis from 2001 through 2012.

The number of PAH-related hospitalizations declined from 3,177 in 2001 to 1,345 in 2012, which was a statistically significant reduction. However, the total number of hospitalizations for all causes in the U.S. did not significantly decrease during that time period.

The mean charges for a PAH-related hospitalization increased from $29,507 per hospitalization in 2001 to $79,607 per hospitalization in 2012. After adjusting for inflation to 2012 dollars, there was a 2.1-fold increase in the mean charges.

In 2001, Medicare paid for 39.8 percent of PAH-related hospitalizations, while private insurance paid for 38.0 percent. In 2012, Medicare paid for 49.4 percent and private insurance paid for 24.9 percent.

During the study, 75 percent of the patients admitted for PAH were women and more than one-third were 45 to 64 years old. Although the number of patients with comorbidities increased from 2001 to 2012, the in-hospital mortality of patients with PAH remained similar: 7.8 percent in 2001 and 6.3 percent in 2012.

After performing a multivariable logistic regression analysis, the researchers found the following factors were independently associated with increased in-hospital mortality: admission to teaching hospitals, fluid and electrolyte imbalance, cardiac dysrhythmias, acute cerebrovascular accident, congestive heart failure, acute kidney injury, cardiogenic shock and acute respiratory failure.

The mean length of hospitalization increased from seven days in 2001 to 7.6 days in 2012. The multivariable logistic regression analysis found the following factors were associated with an increased length of stay: admission to a teaching hospital, pneumonia, acute kidney injury, acute cerebrovascular accident, cardiac dysrhythmias and acute respiratory failure. Older patients had a shorter length of stay in the hospital.

The researchers mentioned a few limitations of the study, including its retrospective design, reliance on claims data and lack of follow-up data. They mentioned that the database did not have laboratory, echocardiographic and hemodynamic data to independently confirm the PAH diagnosis and did not differentiate between first-time hospitalizations and subsequent hospitalizations.

“Taken together, these data highlight the increasing clinical and economic burden of PAH-related hospitalizations and should help identify patients with PAH who are at increased risk of prolonged hospitalization and in-hospital mortality,” the researchers wrote.