Myocardial Infarction Across COVID-19 Pandemic Phases: Insights From the Veterans Health Affairs System

Abstract

Background Cardiovascular procedural treatments were deferred at scale during the COVID-19 pandemic, with unclear impact on patients presenting with non-ST-segment-elevation myocardial infarction (NSTEMI). Methods and Results In a retrospective cohort study of all patients diagnosed with NSTEMI in the US Veterans Affairs Healthcare System from January 1, 2019 to October 30, 2022 (n=67 125), procedural treatments and outcomes were compared between the prepandemic period and 6 unique pandemic phases: (1) acute phase, (2) community spread, (3) first peak, (4) post vaccine, (5) second peak, and (6) recovery. Multivariable regression analysis was performed to assess the association between pandemic phases and 30-day mortality. NSTEMI volumes dropped significantly with the pandemic onset (62.7% of prepandemic peak) and did not revert to prepandemic levels in subsequent phases, even after vaccine availability. Percutaneous coronary intervention and coronary artery bypass grafting volumes declined proportionally. Compared with the prepandemic period, patients with NSTEMI experienced higher 30-day mortality during Phases 2 and 3, even after adjustment for COVID-19-positive status, demographics, baseline comorbidities, and receipt of procedural treatment (adjusted odds ratio for Phases 2 and 3 combined, 1.26 [95% CI, 1.13-1.43], P<0.01). Patients receiving Veterans Affairs-paid community care had a higher adjusted risk of 30-day mortality compared with those at Veterans Affairs hospitals across all 6 pandemic phases. Conclusions Higher mortality after NSTEMI occurred during the initial spread and first peak of the pandemic but resolved before the second, higher peak-suggesting effective adaptation of care delivery but a costly delay to implementation. Investigation into the vulnerabilities of the early pandemic spread are vital to informing future resource-constrained practices.

Keywords: COVID‐19; acute coronary syndrome; acute myocardial infarction; non–ST‐segment–elevation myocardial infarction.

Figure 1. NSTEMI diagnoses and procedural treatment at VA facilities by COVID‐19 phase.

A, NSTEMI incidence across COVID‐19 phases. Volumes of NSTEMI presentations declined in Phase 1, which did not recover to pre‐COVID‐19 levels in subsequent phases. B, Procedure volumes across COVID‐19 phases. Procedural treatments (angiogram/PCI/CABG) for NSTEMI underwent a decline in Phase 1, followed by steady volumes over subsequent phases. CABG indicates coronary artery bypass graft; NSTEMI, non–ST‐segment–elevation myocardial infarction; PCI, percutaneous coronary intervention; and VA, Veterans Affairs.

Figure 2. Kaplan–Meier survival plot by COVID‐19 phases.

Phases 2, 3, and 5 showed significantly higher mortality compared with pre‐COVID‐19 (non‐significant phases not shown).

Figure 3. Adjusted 30‐day mortality at VA facilities by COVID‐19 phase (reference: pre‐COVID‐19 phase).

Compared with the pre‐COVID‐19 phase, higher mortality among patients with NSTEMI was found in Phase 2 and 3 (adjusted for baseline demographics, comorbidities, COVID‐19 status on admission, and receipt of PCI). NSTEMI indicates non–ST‐segment–elevation myocardial infarction; PCI, percutaneous coronary intervention; and VA, Veterans Affairs.

Figure 4. Comparison of 30‐day NSTEMI mortality at VA vs non‐VA facilities across COVID‐19 pandemic phases.

A, Unadjusted 30‐day NSTEMI mortality at VA vs non‐VA facilities by COVID‐19 pandemic phase. Non‐VA facility use peaked during Phases 3 and 5, corresponding to the first and second pandemic peaks. B, Adjusted risk of 30‐day NSTEMI mortality at non‐VA facilities by COVID‐19 phase (reference: VA facilities). Fee‐basis care outside the VA was associated with higher mortality during multiple pandemic phases compared with treatment within the VA (adjustment for demographics and comorbidities). NSTEMI indicates non–ST‐segment–elevation myocardial infarction; and VA, Veterans Affairs.