ANN ARBOR, MICH—So few data exist on the frequency or results of cardiopulmonary resuscitation (CPR) in patients with pulmonary arterial hypertension (PAH) that a study of more than 3,100 PAH patients was recently done to help fill in the blanks.[1]

Of the 513 patients who arrested during the four-year study, 132 (26%) were given CPR. Although in almost all cases CPR was performed in well-equipped facilities and with minimal delays, resuscitation failed 79% of the time. Furthermore, only eight of the 28 patients resuscitated survived for more than 90 days without neurologic deficits.

Though CPR was usually futile, those patients with a defined, rapidly correctable cause of cardiocirculatory arrest had the best chance of survival, Melvyn Rubenfire, MD, one of the investigators, told RESPIRATORY REVIEWS. “Of the eight long-term survivors, seven had correctable causes, such as digitalis toxicity, vasovagal reactions, or pericardial tamponade,” he explained.

There was no hope for survival when cardiocirculatory arrest resulted from a gradual or sudden onset of hypotension or arrhythmias, as was typically the case, stressed Dr. Rubenfire, a Professor of Cardiology at the University of Michigan in Ann Arbor.

The patients were treated for PAH from 1997 through 2000 at 17 referral centers in the United States and Europe. Information on the frequency and results of CPR in these patients was retrospectively obtained from the centers by questionnaire. The study population was estimated at 3,130. The exact numbers of patients treated at two centers during the study period were unknown.

Hemodynamic data collected by right heart catheterization within three months of resuscitation were available for 80 of the 132 patients who received CPR. The data showed a mean pulmonary artery pressure of 61 mm Hg and a mean cardiac index of 1.7 L/min/m2, confirming severe PAH.

PATIENTS RECEIVED THE BEST CARE

Nearly all of the CPR recipients were hospitalized at the time of resuscitation; most were in an intensive care unit or other equally equipped facility. The interval between cardiocirculatory arrest and the start of CPR was less than one minute in 73% of cases.

In 54% of CPR recipients, cardiocirculatory arrest was associated with a significant concomitant illness, most commonly respiratory tract infection. Right heart failure was the most frequent cause of death in these patients, followed by respiratory failure and sudden death.

CPR survivors and non-survivors were not significantly different in age, sex, underlying disease, initial heart rhythm, the interval between arrest and the start of resuscitation, or hemodynamic variables obtained during right heart catheterization. However, there was a trend toward lower right atrial pressures among long-term survivors.

“Our findings, while retrospective, are consistent with clinical experience,” said Dr. Rubenfire. Based on this study, patients being treated for severe PAH at his institution are advised to consider foregoing resuscitation in end-of-life situations.

—Timothy Begany