Mortality rates were high among hospitalized COVID-19 patients in New York City requiring ventilators, researchers found.

The mortality rate for those who received mechanical ventilation was 24.5%, reported Karina Davidson, PhD, of Feinstein Institutes for Medical Research at Northwell Health in Manhasset, New York, and colleagues, writing in JAMA.

As of April 4, among 1,151 patients requiring mechanical ventilation, 3.3% were discharged alive, 72% remained in the hospital, and the remainder were dead.

Outcomes were assessed for 2,634 COVID-19 patients who died or were discharged from 12 New York City area hospitals (i.e., excluding those remaining hospitalized). There were 373 patients (14%) treated in the intensive care unit (ICU), 12.2% receiving invasive mechanical ventilation, and 21% who died.

Of patients who died, the authors found that those with diabetes were more likely to have mechanical ventilation or care in the ICU versus those who did not. Similar findings were seen for patients with hypertension.

The percentage of patients developing acute kidney injury also increased among subgroups with diabetes versus those without diabetes, the authors said. Among patients with outcome data, 3.2% were treated with kidney replacement therapy.

Overall, 5,700 consecutively hospitalized patients from March 1 to April 4 were included in the analysis. Patients were a median age of 63, and almost 40% were women. About 40% were white and 23% were African American. At triage, 31% were febrile, 17% had a respiratory rate greater than 24 breaths per minute, and 28% received supplemental oxygen. About 2% of patients had respiratory co-infections.

Similar to prior data, hypertension, obesity, and diabetes were the most common comorbidities. The authors noted that the median score on the Charlson Comorbidity Index was 4, indicating an estimated 10-year survival rate of 53% and "significant comorbidity burden" in this population.

Among patients admitted to the ICU, the median age was 68, and a third were women, the authors said.

Length of stay was a median of 4 days, though 2.2% of patients were readmitted during the study period, with a median time to readmission of 3 days. The authors noted that readmission rates for patients discharged to a facility, such as a nursing home or rehabilitation center, increased for progressively older age groups versus patients discharged home. Notably, 3,066 patients remained hospitalized at the final study follow-up date, they said.

There were no deaths among patients younger than age 18. Among those with outcome data, 436 patients were younger than age 50 with a score of 0 on the Charlson Comorbidity Index, and only nine died.

Researchers also attempted to shed light on angiotensin-converting enzyme inhibitor (ACEi) and angiotensin II receptor blocker (ARB) use by examining home medication reconciliation information from 2,411 patients who had been discharged or died. Of these, about 8% were taking an ACEi and about 11% were taking an ARB.

"ACEi and ARB medications can significantly increase mRNA expression of cardiac angiotensin-converting enzyme 2 (ACE2), leading to speculation about the possible adverse, protective, or biphasic effects of treatment with these medications," they wrote. "This is an important concern because these medications are the most prevalent antihypertensive medications among all drug classes."

Of the patients taking an ACEi or ARB at home, about half continued to do so in the hospital, while half discontinued their medication. Mortality rates for patients not taking an ACEi or ARB were 26.7%, while they were 32.7% for those taking an ACEi and 30.6% for those taking an ARB, but the authors cautioned these data were unadjusted for known confounders.

Limitations to the data included the New York City study area, that data were collected from an electronic record database and lacked detail of a manual medical record, and that clinical outcome data were only available for less than half of admitted patients, which could have biased the findings, the authors said.