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

Abstract

ObjectiveDeferral 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.MethodsThis 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).ResultsThe 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%).ConclusionOur 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.

Deferral of non-emergency cardiac interventions is associated with increased emergency hospitalizations up to 24 months post-procedure

“…In a study of patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), a positive correlation between NT-proBNP and MACE within 1 month was observed [ 20 ]. Previous analysis of the present collective yielded comparable results, with MACE being predicted by elevated NT-proBNP levels after the waiting time [ 5 , 8 ]. This raises the question of whether the performance of a procedure even after deferral may reverse myocardial damage.…”

“…We calculated a threshold of 808.5 pg/ml corresponding to previously described cut-points of > 900 pg/ml for accurately identifying acute heart failure in the age group of 70 to 75 years [ 21 ], similar to the mean age of the patients in our study. Moreover, it is comparable to the cut-point calculated in the 12 months outcomes analysis of this cohort [ 8 ]. This strengthens the hypothesis that poor outcomes following deferral of cardiac interventions are mainly due to pre-procedure acute heart failure.…”

“…NT-proBNP has already been proven to be a suitable risk indicator for the current cohort, predicting poor outcomes, including primary endpoint event rates, at 12 months [ 8 ]. Since the period of increased risk due to deferral has been identified, we aimed to assess the predictive value of NT-proBNP levels for primary endpoint events during this period.…”

“…Consistent with this, BNP and NT-proBNP are most commonly used in diagnosis and follow-up of patients with acute heart failure [ 15 ]. Moreover, NT-proBNP has been approved to be suitable for assessing risk of MACE in deferred patients [ 6 ], even in the present cohort [ 5 , 8 ]. In the present study, patients not experiencing emergency hospitalization or death within 36 months of follow-up showed stable concentrations of NT-proBNP levels indicating an overall stable condition.…”