STEMI Door-to-Balloon Times Haven’t Suffered During COVID-19: NACMI

(UPDATED) Patients with STEMI and COVID-19 are uniquely high risk, North American registry data show. And for patients whose door-to-balloon (D2B) times are similar to those without the viral disease, researchers say, primary PCI is “preferable and feasible.”

COVID-19’s implications for STEMI are well known—many people experiencing heart attack symptoms have put off care during the pandemic, for example, and among patients hospitalized with the SARS-CoV-2 virus, 15% have elevated troponins, investigator Timothy Henry, MD (The Christ Hospital, Cincinnati, OH), said in a late-breaking session today during TCT Connect 2020.

Presenting results from the North American COVID-19 ST-Segment Elevation Myocardial Infarction (NACMI) registry, he pointed out that thus far there have been only five publications, totaling 174 patients, on STEMI in the context of COVID-19. Trends are emerging: in-hospital presentation is frequent, thrombotic lesions are common (with some reports of microthrombi), ST-segment elevation has been seen in the absence of culprit lesions (ranging from 5% to 55% among the studies), and mortality rates are increased (ranging from 12% to 72%).

“There’s been considerable controversy,” Henry said, over what to do with a COVID-19-positive patient with ST-segment elevation who comes to the cath lab. Guidelines for management, first published in April 2020 with Henry as senior author, emphasize primary PCI as the gold standard. “A fibrinolysis-based strategy may be entertained at non-PCI capable referral hospitals or in specific situations where primary PCI cannot be executed or is not deemed the best option,” the document states.

Celina M. Yong, MD, MBA, MSc (Stanford University and VA Palo Alto Healthcare System, CA), who didn’t take part in NACMI, told TCTMD that she’s impressed by the speed with which the registry was created. “I think it really sets a new standard for how efficiently we can collaborate across countries,” she commented. She agreed that the message to prefer primary PCI has been widely applied and, as the main “strategy, even with the precautions we take for COVID-19 patients, is totally viable and effective.”

The NACMI registry—a collaborative effort by the Society for Cardiovascular Angiography and Interventions, the Canadian Association of Interventional Cardiology, and the American College of Cardiology’s interventional council—sought to fill in the knowledge gaps, with the goal being “to develop data-driven treatment plans and guidelines for these unique patients,” Henry said during his TCT Connect presentation.

A lot of times people will pooh-pooh observational data, but this is exactly the type of data that we need to be able to gather information about what our practices are. Ajay Kirtane

As of October 4, 2020, NACMI investigators had enrolled 594 adults at 64 sites: 171 of these individuals were confirmed COVID-19-positive and 423 were persons under investigation (PUI) who tested negative after being suspected of having COVID-19. All had either ST-segment elevation or new-onset left bundle branch block on 12-lead ECG, as well as a clinical signs of ischemia, such as chest/abdominal discomfort, dyspnea, cardiac arrest, shock, or need for mechanical ventilation. There were no exclusion criteria.

These two populations (COVID-19-positive and PUI) were compared to a propensity-matched cohort from the Midwest STEMI Consortium. There were no differences in age and sex across the three groups. Diabetes was more common in the COVID-19 patients than in the PUI (44% vs 33%). Additionally, as Henry stressed, there were “really prominent” disparities when it came to race/ethnicity. Black, Asian, and Hispanic patients represented 27%, 7%, and 24%, respectively, of the COVID-19 group, but made up only 11%, 6%, and 6% of the PUI group. By comparison, 93% of the controls were white, while just 4% were Black, 1% were Asian, and 1% were Hispanic (P < 0.001).

The COVID-19 group was no more likely than the PUI and matched groups to present with cardiac arrest. However, they were more apt to have cardiogenic shock (20% vs 14% vs 5%) and had lower ejection fraction (45% vs 45% vs 50%). Compared with the PUI group, COVID-19 patients more often had chest X-ray infiltrates (49% vs 17%) and dyspnea (58% vs 38%) but no increase in in-hospital STEMI.

Fully 21% of COVID-19 patients with STEMI did not undergo angiography, compared with 5% of the PUI and none of the matched cohort. Primary PCI rates across the three groups were 71%, 80%, and 81%. Median door-to-balloon times were similar at 80, 78, and 86 minutes, respectively. Henry said he was surprised to see that nearly four in five COVID-19 patients had angiography, calling this a positive sign that “in general in North America, we’ve been relatively aggressive with these patients.”

Thrombolytics were rarely given: to 6% of the COVID-19 patients, 2% of PUI, and 3% of the matched cohort.

In-hospital death was increased and hospital stays were longer for COVID-19 patients compared with both the PUI and propensity-matched group (P< 0.001). For in-hospital stroke, the difference reached significance only when compared with the propensity-matched patients (P = 0.039). ICU stays also were longer for COVID-19 patients versus PUI. Reinfarction rates were similar.

In-Hospital Outcomes of STEMI

Based on these results, Henry said it appears that North American centers are following the guidance to perform primary PCI when possible. Yong, too, described the D2B times as “excellent,” especially considering the need to handle not only STEMI but also COVID-19. “Every added layer of complexity adds time, but it was really promising to me that they still [were so fast],” she said.

TCT Course Director Ajay Kirtane, MD (NewYork-Presbyterian/Columbia University Irving Medical Center, New York, NY), said yesterday in a media briefing: “I think that COVID has been something that everyone has been overburdened with and a lot of times people will pooh-pooh observational data, but this is exactly the type of data that we need to be able to gather information about what our practices are, how they’ve been. I think many of us around the world will see these data, and it will echo their own experience.”

Also speaking to the press, Adnan Kastrati, MD (Deutsches Herzzentrum München, Munich, Germany), said that he was “amazed” to see that D2B times didn’t differ, “because in our experience you need more time for protective measures, for personal protection, etc. So this is a great thing that they achieved.” At his center, he added, they’ve relied solely on primary PCI and not administered fibrinolysis.

Henry pointed out that this is the first look at the NACMI data. “There will be considerable ongoing evaluation of this,” he said. For example, the investigators will look at mortality levels in patients who didn’t receive angiography. “I can tell you briefly that the lowest mortality is in the patients who actually underwent PCI, but of course that’s a selected group, and we have to be careful [in interpreting] that at this time.”

Another thing yet to be analyzed are the times from chest-pain onset to presentation. “It’s certainly possible that that is longer than the door-to-balloon time,” Henry acknowledged. “What we’re very confident [in] is that the door-to-balloon times were not [affected].”

Enrollment is ongoing, and Henry said NACMI hopes to expand to other sites in areas with high COVID-19 prevalence, Mexico, and possibly South America. This may expose regional variations. Other analyses will look at how practices and outcomes may have changed over the course of the pandemic. Follow-up will continue through 1 year.

Speaking with TCTMD, Yong drew attention the “stark racial and ethnic differences” uncovered by the registry. “As our country struggles with persistent challenges in reaching health equity, this study highlighted many important questions ranging from biologic differences to social determinants of health and access to resources during the pandemic,” she said.

It may simply reflect a higher COVID-19 rate in these populations, Yong suggested, or it may be that Black and Hispanic patients with COVID-19 are for some reason at higher risk of MI. Moreover, minority patients may have presented to hospitals under more strain during the pandemic or had delays in being able to obtain care. As the NACMI investigators dig into their data, she hopes to get a closer look at comorbidities and other factors to explain these patterns.