Primary percutaneous coronary intervention (PPCI) and being younger in age were both protective against death in COVID-19-positive patients with ST-segment elevation myocardial infarction (STEMI) in the ongoing NACMI registry – the largest study on this group of patients.
This is according to the latest study updates presented during a late-breaking presentation at the Society for Cardiovascular Angiography & Interventions (SCAI) 2021 Virtual Sessions on Wednesday by Payam Dehghani, MD, University of Saskatchewan.
Data from the 1,507 patients now recruited also shows that diabetes is an “important multivariate predictor of death” in COVID-19-positive STEMI, said Dehghani, while – in line with findings reported earlier this month in 1,185 patients – inequalities in outcomes based on ethnicity continued to be highlighted.
As in the previous analysis of the ongoing study, patients with COVID-19 were found to be a “unique demographic” with specific clinical characteristics and high in-hospital cardiac events, the researchers on the current study added.
The North American COVID-19 and STEMI (NACMI) registry was created under the guidance of three North American cardiovascular associations – SCAI, the Canadian Association of Interventional Cardiologists and the American College of Cardiology Interventional Council – in response to evidence that cardiovascular disease patients are more susceptible to severe forms of the infection.
Myocardial injury is also known to be highly prevalent among hospitalized patients, affecting as many as 20% to 30%.
The registry includes patients over 18 years of age with STEMI or new left bundle branch block who are confirmed to be COVID-19-positive (301 as of Wednesday’s report), those with suspected infection, known as “persons under investigation” or PUI (604) – who eventually turned out to be negative – and a control group of 602 STEMI patients treated prior to the pandemic (between 2015 and 2019) who were age- and sex-matched to the COVID-19-positive group in a 2:1 ratio.
According to the current update, the primary outcome, a composite of in-hospital death, stroke, recurrent myocardial infarction or repeat unplanned revascularization, occurred in 36% of the COVID-19-positive group, versus 13% of PUI and 5% of control patients (p<0.001 relative to controls).
“One in three of them does not make it out (of hospital),” Dehghani said.
“Most of this in-hospital outcome is driven significantly with mortality,” he added. “Not unexpectedly, (COVID-19 patients had) higher longer ICU stays, and much longer total length of stay.”
Dehghani noted that a higher proportion of the COVID-19-positive patients were dyspneic (51% with dyspnea on presentation vs. 35% in the PUI group; p<0.001), and had infiltrates (45% of COVID-19-positive group vs. 16% of PUI; p<0.001), but that fewer of the COVID-19 group had chest pain on presentation (53% vs. 80%; p<0.001).
The findings thus far on the study also point to inequalities in outcomes for different ethnic groups, with COVID-19-positive patients more likely to have a “minority ethnicity” (p<0.001). In the COVID-19-positive cohort, 55% of patients were non-Caucasian, compared to 25% in PUI (p<0.001).
“We have never seen a cohort of MIs (myocardial infarctions) where we have 55% non-Caucasian,” said Dehghani.
He added that 44% of those with COVID-19 were diabetic, compared to just 33% of those in the PUI group, “which was significant” at p<0.001.
“Importantly, we looked at predictors of death in the COVID-positive patient population presenting with (STEMI),” he said. “Some of this is intuitive to us, intubated patients, shock pre-PCI. But presentation in-house was common.
“Diabetes came out as an important predictor, a multivariate predictor of death.”
Age also protected against mortality in all-comer groups, as did PCI, he said.
The current study also gave updates on perfusion strategy, a matter that has been controversial during the pandemic.
As with many other healthcare services, timely access to PPCI has been impacted during the pandemic. Authors on the previous NACMI results report, led by Santiago Garcia, MD, from the Minneapolis Heart Institute Foundation, said earlier this month that one strategy has been to shift to pharmacological reperfusion to avoid delays, protect resources and essential healthcare workers.
Publications from China and Europe previously cited the importance of thrombolytic drugs in reperfusion, Dehghani said, though stressed that the American College of Cardiology guidelines suggest “that is probably not a good idea”.
“You can see that reflected in the way patients were being treated, less than 3% of COVID-positive were given thrombolytics – primary PCI was the dominant reperfusion modality.”
Among the COVID-19-positive patients who received angiography, 71% received PPCI and 23% had no culprit vessels identified on angiography (both p < 0.001 relative to controls).
Nevertheless, in the current study, Dehghani and colleagues reported that the COVID-19-positive patients were more likely to undergo medical therapy as the primary perfusion therapy (p<0.001 relative to PUI). This had to do with “how sick this patient population is and how they had significant comorbidities, including intubation and respiratory illness,” said Dehghani.
He added that 1 in 5 of the COVID-19-positive patients who underwent angiography had no culprit vessel identified.
“Of the patients who have culprit disease, PCI was similar in success rate to both groups and fairly comparable to pre-pandemic numbers,” he said. Although his presentation did not include exact door-to-balloon times, he said more than 70% come in under the 90-minute range.
Dehghani went on to reiterate conclusions from the previous analysis that PPCI is “common, it’s feasible, and it’s associated with reduced mortality. This is in-keeping with our current guidelines”.
The registry is still recruiting patients, and the researchers are keen to ask a significant number of additional questions, including over “angiographic core lab and angiographic EKG (electrocardiogram), to be able to identify patterns.”
Asked whether it has been possible to isolate how much of an additional contributor STEMI events were to observed mortality in COVID-19-positive patients, Dehghani noted difficulties in determining cause of death for these patients.
“If you look at all-coming autopsy of everyone who dies, about 40% will actually have microthrombi in their coronary arteries, so it becomes very difficult,” he said.
“One way we’ve gotten around it is to ask our colleagues, cardiologists in ICU care, to come up with scores of a gestalt of how sick or critically ill in terms of non-cardiac (issues) that these patients may be, and perhaps looking at mortality difference.”