Severe COVID-19 Infection Can Lead to Acute PH, Raising Risk of Death

Acute pulmonary hypertension (aPH) is frequent and linked with a higher risk of mortality in people who are severely ill with COVID-19, according to a Swedish study.

The study, “Acute pulmonary hypertension and short-term outcomes in severe Covid-19 patients needing intensive care,” was published in the journal Acta Anaesthesiologica Scandinavica.

Severe COVID-19 is characterized by inflammation in the lungs and an increased risk of blood clots. These could set the stage for pulmonary hypertension — when the blood pressure in the vessels that bring blood to the lungs (pulmonary blood pressure) is abnormally high. However, published data is scant on pulmonary hypertension in COVID-19 patients.

Researchers in Sweden assessed records for 67 people being treated for severe COVID-19 infection at Karolinska University Hospital in Solna, whose aPH was established using an imaging method called transthoracic echocardiography (TTE). TTE is a noninvasive way of evaluating the heart and its vessels.

Of these 67 patients —all enrolled between April and May 2020 — 26 (39%) had aPH, as defined by a systolic acute pulmonary artery pressure higher than 35 mm Hg, based on measurements taken during TTE.

Among those without aPH, three (7%) died within 21 days of performing TTE. Significantly more of the patients with aPH, 12 or 46%, also died within those three weeks. A similar difference was found in comparisons of survival rates 30 days after admission to an intensive care unit (ICU).

More people with acute pulmonary hypertension also needed mechanical ventilation to support breathing at 21 days after TTE, compared with those without aPH (20 vs. 11).

Additional analyses showed that patients in the aPH group had significantly higher blood levels of NTproBNP (a marker of heart failure) and troponin T — a marker of damage to heart muscles — on the day of TTE. However, levels of D-dimer (a marker of blood clotting) did not differ significantly between the groups.

“The main finding of this study was that approximately 40% of Covid-19 patients treated in an ICU were diagnosed with acute pulmonary hypertension as per established echocardiographic criteria,” the researchers wrote.

Among this study’s limitations were the use of TTE, which can be a challenging or inaccurate way of diagnosing aPH. Generally, more invasive tests are more accurate, but such tests were not feasible in the setting of patients being treated for severe COVID-19.

Also, no standardization of the timing of TTE was possible due to “existing circumstances,” resulting in a variable time point in relation to ICU admission.

“However, the presence of aPH at any time during the ICU stay (early, intermediate, or late) appeared to translate to a worse short-term outcome,” they wrote.