Six Months After the Patients Stayed Home: A Nationwide Study of Cardiac Mortality and Readmissions Following the First Wave of the COVID-19 Pandemic in Malta.

Background The first COVID-19 wave resulted in a significant decline in acute cardiac admissions (ACAs) and delays to hospital presentation in Malta, as well as an excess of out-of-hospital cardiac arrests. The aim was to investigate the impact of the observed delays in presentation in 2020 on mortality and cardiac readmissions at six months. Methods All ACAs between 28th February and 30th April 2020 (first wave of COVID-19 in Malta) were included, and the corresponding 2019 period was used as a control. ACA was defined as an unplanned admission of an adult (aged ≥16 years) under the care of a cardiologist. Outcomes over the six months following the index ACA included death, cardiac readmission, and planned cardiac intervention at discharge. The term 'death' referred to all-cause mortality. Cardiac readmissions referred to unplanned admissions for acute cardiac pathology following the index ACA. During sub-analyses, ACAs were divided into acute coronary syndrome (ACS) and non-ACS. A first analysis compared the frequency of deaths, cardiac readmissions, and planned interventions between the 2019 and 2020 cohorts. A second analysis investigated differences in six-month survival and freedom from readmission between the two cohorts. Both analyses were followed by a sub-analysis. Results There were 330 ACAs among the 2019 cohort and 220 in 2020. There were no significant differences between the 2019 and 2020 cohorts in all-cause mortality (2019, 8.8% vs 2020, 8.2%, p=0.466) and Kaplan-Meier survival estimates at a six-month follow-up (2019, 169.06 days (95% CI 164.95-173.17) vs 2020, 168.27 days (95% CI 162.82-173.72), p=0.836), including subgroup analysis for non-ACS (2019, 168.52 days (95% CI 163.08-173.96) vs 168.11 days (95% CI 160.93-175.30), p=0.952) and ACS patients (169.81 days (95% CI 163.54-176.09) in 2019 vs 168.45 days (95% CI 160.17-176.73) in 2020, p=0.739). A significantly higher number of patients from the 2019 cohort (75/319, 23.5%) required readmission compared to 2020 (32/212; 15.1%) (p=0.02). Similarly, there was shorter freedom from cardiac readmission among 2019 patients (mean 150.98 days (95% CI 144.63-157.33)) compared to 2020 patients (mean 158.66 days (95% CI 151.58-165.74, p=0.024). During sub-analysis, the difference in freedom from readmission was significant only for non-ACS patients (mean of 145.45 days (95% CI 136.58-154.32) in 2019 vs 158.92 days (95% CI 149.19-168.64) in 2020, p=0.018). Analysis of cardiac interventions during the six months post-index ACA discharge showed significantly more planned cardiac interventions in 2019 (52/319; 16.3%) compared to 2020 (20/212; 9.4%) (p=0.027). Conclusions A delay in presentation of ACAs during COVID-19 in Malta resulted in lower readmission rates and increased freedom from readmissions, with no excess in all-cause mortality at a six-month follow-up. The reasons for the optimistic outcomes of patients admitted during the first wave of COVID-19 may be multifactorial. Reasons may include ongoing fear of hospital presentation, a more holistic approach to patients' in-hospital care during 2020 aimed at reducing further hospital contact post-discharge, and a selection bias secondary to an excess of out-of-hospital cardiac arrests during the initial wave of COVID-19. Further studies will be required to truly assess the collateral impact of non-COVID-19-related illness. Public education on cardiovascular health is vital and must be emphasized during the pandemic.