Predictors of worse outcome after postponing non-emergency cardiac interventions during the COVID-19 pandemic

OBJECTIVE: Deferral of non-emergency cardiac procedures is associated with increased early emergency cardiovascular hospitalisation. This study aimed to identify predictors of worse clinical outcome after deferral of non-emergency cardiovascular interventions. METHODS: This observational case-control study included consecutive patients whose non-emergency cardiac intervention has been postponed during COVID-19-related lockdown between 19 March and 30 April 2020 (n=193). Cox regression was performed to identify predictors of the combined 1-year end point emergency cardiovascular hospitalisation and death. All patients undergoing non-emergency interventions in the corresponding time period 2019 served as control group (n=216). RESULTS: The combined end point of death and emergency cardiovascular hospitalisation occurred in 70 (36.3%) of 193 patients with a postponed cardiovascular intervention. The planned intervention was deferred by a median of 23 (19–36) days. Arterial hypertension (HR 2.27; 95% CI 1.00 to 5.12; p=0.049), chronic kidney disease (HR 1.89; 95% CI 1.03 to 3.49; p=0.041) as well as severe valvular heart disease (HR 3.08; 95% CI 1.68 to 5.64; p<0.001) were independent predictors of death or emergency hospitalisation. Kaplan-Maier estimators of the combined end point were 31% in patients with arterial hypertension, 56% in patients with severe valvular heart disease and 77% with both risk factors (HR 12.4, 95% CI 3.8 to 40.7; p<0.001) and only 9% in patients without these risk factors (log rank p<0.001). N-terminal pro-B-type natriuretic peptide (NT-proBNP) cut-point of ≥1109 pg/mL best predicts the occurrence of primary end point event in deferred patients (area under the curve 0.71; p<0.001; sensitivity 63.8%, specificity 69.4%). CONCLUSION: Our results suggest that patients with either arterial hypertension, chronic kidney or severe valvular heart disease are at very high risk for emergency hospitalisation and increased mortality in case of postponed cardiac interventions even in supposed stable clinical status. Risk seems to be even higher in patients suffering from a combination of these conditions. If the ongoing or future pandemics force hospitals again to postpone cardiac interventions, the biomarker NT-proBNP is an applicable parameter for outpatient monitoring to identify those at risk for adverse cardiovascular events.