A case series of US experience with COVID-19 has upheld suggestions of a link with cardiomyopathy, which developed in 33% of intensive care patients.
In a research letter published in the Journal of the American Medical Association, Matt Arentz (Department of Global Health, University of Washington, Seattle, USA) and colleagues describe the clinical presentation, characteristics, and outcomes of incident cases of COVID-19 admitted to the intensive care unit (ICU) at Evergreen Hospital in Kirkland, Washington, where one of the first deaths in the USA was reported.
They say: “It is unclear whether the high rate of cardiomyopathy in this case series reflects a direct cardiac complication of SARS-CoV-2 infection or resulted from overwhelming critical illness. Others have described cardiomyopathy in COVID-19, and further research may better characterise this risk.”
Evergreen Hospital is a 318-bed public hospital with a 20-bed ICU serving approximately 850 000 residents of King and Snohomish counties in Washington State. Following the first reported death, multiple cases of COVID-19 were identified in the surrounding community over the following weeks, and treated at Evergreen Hospital. Most were attributed to US transmission, and the majority were linked to exposures at a skilled nursing facility.
Patients with confirmed SARS-CoV-2 infection (positive result by polymerase chain reaction testing of a nasopharyngeal sample) admitted to the ICU at Evergreen Hospital between 20 February and 5 March 2020 were included in the series. Laboratory testing was reviewed at ICU admission and on day five. Chest radiographs were reviewed by an intensivist and a radiologist. Patient outcome data were evaluated after ≥five days of ICU care or at the time of death. No analysis for statistical significance was performed given the descriptive nature of the study.
In all, 21 cases were included (mean age 70 years, range 43–92 years, 52% male). Comorbidities were identified in 18 cases (86%), with chronic kidney disease and congestive heart failure being the most common. Initial symptoms included shortness of breath (76%), fever (52%), and cough (48%). Mean onset of symptoms before presenting to the hospital was 3.5 days, and 17 patients (81%) were admitted to the ICU <24 hours after hospital admission.
An abnormal chest radiograph was observed in 20 patients (95%) at admission. The most common findings on initial radiograph were bilateral reticular nodular opacities (n=11, 52%) and ground-glass opacities (n=10, 48%). By 72 hours, 18 patients (86%) had bilateral reticular nodular opacities and 14 (67%) had evidence of ground-glass opacities. The mean white blood cell count was 9365μL at admission, and 14 patients (67%) had a white blood cell count in the normal range. Fourteen patients (67%) had an absolute lymphocyte count of less than 1000 cells/μL. Liver function tests were abnormal in eight patients (38%) at admission.
Mechanical ventilation was initiated in 15 patients (71%). Acute respiratory distress syndrome (ARDS) was observed in all patients (15 of 15) requiring mechanical ventilation and eight of 15 (53%) developed severe ARDS by 72 hours. Although most patients did not present with evidence of shock, vasopressors were used for 14 patients (67%) during the illness. Cardiomyopathy developed in seven patients (33%). Only 52% of these had a history of heart disease and presented with global systolic dysfunction or regional wall motion abnormalities in a non-vascular distribution. As of 17 March 2020, mortality was 67% and 24% of patients remained critically ill; 9.5% have been discharged from the ICU.
The authors describe it as the “first description of critically ill patients infected with SARS-CoV-2 in the US. These patients had a high rate of ARDS and a high risk of death, similar to published data from China. However, this case series adds insight into the presentation and early outcomes in this population and demonstrates poor short-term outcomes among patients requiring mechanical ventilation.”
Limitations include the small number of patients from a single centre, and that the study population included older residents of skilled nursing facilities, and is not likely to be broadly applicable to other patients with critical illness. But the researchers say that it “provides some initial experiences regarding the characteristics of COVID-19 in patients with critical illness in the US, and emphasises the need to limit exposure of nursing home residents to SARS-CoV-2”.