Cardiovascular subphenotypes in patients with COVID‐19 pneumonitis whose lungs are mechanically ventilated: a single‐centre retrospective observational study

Abstract

Summary Unsupervised clustering methods of transthoracic echocardiography variables have not been used to characterise circulatory failure mechanisms in patients with COVID‐19 pneumonitis. We conducted a retrospective, single‐centre cohort study in ICU patients with COVID‐19 pneumonitis whose lungs were mechanically ventilated and who underwent transthoracic echocardiography between March 2020 and May 2021. We performed latent class analysis of echocardiographic and haemodynamic variables. We characterised the identified subphenotypes by comparing their clinical parameters, treatment responses and 90‐day mortality rates. We included 305 patients with a median (IQR [range]) age 59 (49–66 [16–83]) y. Of these, 219 (72%) were male, 199 (65%) had moderate acute respiratory distress syndrome and 113 (37%) did not survive more than 90 days. Latent class analysis identified three cardiovascular subphenotypes: class 1 (52%; normal right ventricular function); class 2 (31%; right ventricular dilation with mostly preserved systolic function); and class 3 (17%; right ventricular dilation with systolic impairment). The three subphenotypes differed in their clinical characteristics and response to prone ventilation and outcomes, with 90‐day mortality rates of 22%, 42% and 73%, respectively (p < 0.001). We conclude that the identified subphenotypes aligned with right ventricular pathophysiology rather than the accepted definitions of right ventricular dysfunction, and these identified classifications were associated with clinical outcomes.

Protecting the right ventricle in COVID‐19 pneumonitis: a missing piece of the puzzle?

“…showed that right ventricular dilatation, analogous to early injury, was associated with renal dysfunction and increased mortality [ 5 ]. Over half of those with the ‘class 2’ phenotype (isolated dilatation) required renal replacement therapy [ 1 ]. This could plausibly be associated with multisystem thrombotic disease, for which higher doses of low molecular weight heparin are now titrated with plasma anti‐Xa monitoring.…”

“…Chotalia et al. labelled the class 3 phenotype as ‘right ventricular failure’ [ 1 ]. In this class: 23% required a second vaso‐active agent; 31% had normal left ventricular ejection fraction; and 56% had a hyperdynamic left ventricle.…”

“…Key to identifying those targets is a multimodal approach to diagnosis and monitoring. Echocardiography was performed at a median of 8 days after admission to ICU by Chotalia et al, which makes assessment of response to treatment practically impossible and disease monitoring rather challenging [ 1 ]. We recommend echocardiography at the time of referral to ICU and daily scans thereafter (for the duration of invasive mechanical ventilation).…”

“…observed an improvement in the degree of hypercapnia in the class 2 phenotype, likely reflecting an improvement in respiratory mechanics and minute ventilation. However, they did not provide details on pulmonary mechanics (in particular plateau and driving pressures) or physiological variables before and after prone positioning [ 1 ]. Thus, patients with COVID‐19 pneumonitis and evidence of ‘early’ injury may benefit from prone positioning to mitigate both progression of lung and right ventricular injury, even when gas exchange is within acceptable parameters (Fig.…”

“…In this issue of Anaesthesia , Chotalia et al. report their retrospective observations of 305 critically unwell patients with COVID‐19 pneumonitis who underwent an echocardiographic examination at some stage during their ICU stay [ 1 ]. They were able to construct three different groups with shared clinical characteristics, right ventricular performance metrics and outcomes.…”