Prolonged QTc in hospitalized COVID-19 patients tied to increased mortality risk

Prolonged corrected QT interval (QTc), as determined via electrocardiogram (ECG), may indicate an elevated risk of myocardial injury and death in patients hospitalized for COVID-19, according to a prospective study from Israel presented at EHRA 2022.

“Prolonged QTc is an independent risk factor for both myocardial injury and 1-year mortality among patients hospitalized with COVID-19 infection,” noted study lead author Dr Ariel Banai from the Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.

“Our study suggests that a simple ECG tracing performed upon admission may help healthcare professionals to triage patients with COVID-19 and identify those in need of intensive care,” he said.

Participants were 335 consecutive patients who had been hospitalized due to COVID-19 and undergone echocardiographic assessment within 48 hours of admission. A total of 109 patients (32.5 percent) were considered to have prolonged QTc, which in this study was defined as ≥440 and ≥450 msec in men and women, respectively.

Compared with those with normal QTc, patients with prolonged QTc had more comorbidities (eg, diabetes [50.5 percent vs 28.3 percent; p<0.001], hypertension [67 percent vs 46 percent; p<0.001]) and more often had severe (vs mild) COVID-19 disease. They were also older than their counterparts with normal QTc (70 vs 62.7 years; p<0.001).

The risk of myocardial injury, identified through elevated cardiac biomarkers (troponin in the bloodstream) and/or myocardial dysfunction on ECG, was raised in patients with vs without prolonged QTc (71.6 percent vs 48.7 percent; adjusted* hazard ratio [adjHR], 2.07, 95 percent confidence interval [CI], 1.22–3.5; p=0.007). [EHRA 2022, abstract N° 40995]

At 1 year, the mortality rate was also significantly higher among patients with vs without prolonged QTc (41 percent vs 17 percent; adjHR, 1.85, 95 percent CI, 1.2–2.84; p=0.005).

The mortality risk at 1 year was greatest in patients with both prolonged QTc and myocardial injury compared with those without both conditions (adjHR, 6.63, 95 percent CI, 2.28–19.3; p=0.001). The risk was also significantly elevated in patients with prolonged QTC and no myocardial injury (adjHR, 6.12, 95 percent CI, 1.83–20.49; p=0.003) and in patients with myocardial injury and no QTc prolongation (adjHR, 4.95, 95 percent CI, 1.83–20.49; p=0.003).

“QT interval prolongation is common in critically ill patients and is associated with increased mortality,” said Banai, pointing out that its effect in determining myocardial injury and death in patients hospitalized with COVID-19 is uncertain.

“In our study, one-third of hospitalized COVID-19 patients had a prolonged QT interval. These patients were generally older and sicker but even after adjusting for these factors, prolonged QT interval was independently associated with worse survival,” he said.

Banai further highlighted the usefulness of echocardiography in identifying myocardial injury in this study. “Interestingly, among patients with myocardial injury, half had no troponin in the blood, suggesting blood tests alone may miss a substantial number of patients with this heart problem,” he noted.

“An ECG is an inexpensive, non-invasive, easily attainable, and widely available test applied in nearly all hospitalized patients. [T]he results [of this study] indicate that ECG assessment could play a role in the risk stratification of patients admitted [to hospital] with COVID-19 infection,” he concluded, citing the need for further research to confirm these findings.