Cited 54 times since 2013 (7.1 per year) source: Scopus European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Volume 44, Issue 5, 07 March 2013, Pages 875-883 Evaluation of cardiac surgery mortality rates: 30-day mortality or longer follow-up? Siregar S, Groenwold RH, de Mol BA, Speekenbrink RG, Versteegh MI, Brandon Bravo Bruinsma GJ, Bots ML, van der Graaf Y, van Herwerden LA


The aim of our study was to investigate early mortality after cardiac surgery and to determine the most adequate follow-up period for the evaluation of mortality rates.


Information on all adult cardiac surgery procedures in 10 of 16 cardiothoracic centres in Netherlands from 2007 until 2010 was extracted from the database of Netherlands Association for Cardio-Thoracic Surgery (n = 33 094). Survival up to 1 year after surgery was obtained from the national death registry. Survival analysis was performed using Kaplan-Meier and Cox regression analysis. Benchmarking was performed using logistic regression with mortality rates at different time points as dependent variables, the logistic EuroSCORE as covariate and a random intercept per centre.


In-hospital mortality was 2.94% (n = 972), 30-day mortality 3.02% (n = 998), operative mortality 3.57% (n = 1181), 60-day mortality 3.84% (n = 1271), 6-month mortality 5.16% (n = 1707) and 1-year mortality 6.20% (n = 2052). The survival curves showed a steep initial decline followed by stabilization after ∼60-120 days, depending on the intervention performed, e.g. 60 days for isolated coronary artery bypass grafting (CABG) and 120 days for combined CABG and valve surgery. Benchmark results were affected by the choice of the follow-up period

four hospitals changed outlier status when the follow-up was increased from 30 days to 1 year. In the isolated CABG subgroup, benchmark results were unaffected

no outliers were found using either 30-day or 1-year follow-up.


The course of early mortality after cardiac surgery differs across interventions and continues up to ∼120 days. Thirty-day mortality reflects only a part of early mortality after cardiac surgery and should only be used for benchmarking of isolated CABG procedures. The follow-up should be prolonged to capture early mortality of all types of interventions.

Keywords: Database, Statistics, Cardiac surgery, Outcomes, Health Policy, Risk Analysis/modelling

Eur J Cardiothorac Surg. 2013 Mar;44(5):875-883