Multi-centre prospective internal and external evaluation of the Brompton Harefield Infection Score (BHIS).

BACKGROUND: Previously, we reported that the Brompton Harefield Infection Score (BHIS) accurately predicts surgical site infection (SSI) after coronary artery bypass grafting (CABG). The BHIS was developed using two-centre data and stratifies SSI risk into three groups based on female gender, diabetes or HbA1c > 7.5%, body mass index ≥ 35, left ventricular ejection fraction < 45% and emergency surgery. The purpose of this study was to prospectively evaluate BHIS internally as well as externally. METHODS: Multi-centre prospective evaluation involving three tertiary centres took place between October 2012 and November 2015. SSI was classified using the Public Health England protocol. Receiver operating characteristic (ROC) curves assessed predictive accuracy. RESULTS: Across the four hospital sites, 168 of 4308 (3.9%) CABG patients had a SSI. Categorising the hospitals by BHIS score revealed that 65% of all patients were low risk (BHIS 0-1), 26% were medium risk (BHIS 2-3) and 8% were high risk (BHIS ≥ 4). The area under the ROC curve was in the range of 0.702-0.785. Overall area under the ROC curve was 0.709. CONCLUSIONS: BHIS provides a novel, internally and externally evaluated score for a patient's risk of SSI after CABG. It enables clinicians to focus on strategies to prospectively identify high-risk patients and improve outcomes.

Mortality, stroke, and heart failure in atrial fibrillation cohorts after ablation versus propensity-matched cohorts.

BACKGROUND: We sought to determine from key clinical outcomes whether catheter ablation of atrial fibrillation (AF) is associated with increased survival. METHODS AND RESULTS: Using routinely collected hospital data, ablation patients were matched to two control cohorts using direct and propensity score methodology. Four thousand nine hundred ninety-one ablation patients were matched 1:1 with general AF controls without ablation. Five thousand four hundred seven ablation patients were similarly matched to controls who underwent cardioversion. We examined the rates of ischemic stroke or transient ischemic attack (stroke/TIA), heart failure hospitalization, and death. Matched populations had very similar comorbidity profiles, including nearly identical CHA2DS2-VASc risk distribution (p=0.6948 and p=0.8152 vs general AF and cardioversion cohorts). Kaplan-Meier models showed increased survival after ablation for all outcomes compared with both control cohorts (p<0.0001 for all outcomes vs general AF, p=0.0087 for stroke/TIA, p<0.0001 for heart failure, and p<0.0001 for death vs cardioversion). Cox regression models also showed improved survival after ablation for all outcomes compared with the general AF cohort (hazard ratio [HR]=0.4, 95% confidence interval [95% CI]: 0.3-0.6, p<0.0001 for stroke/TIA; HR=0.4, 95% CI: 0.2-0.6, p<0.0001 for heart failure; HR=0.1, 95% CI: 0.1-0.1, p<0.0001 for death) and the cardioversion cohort (HR=0.6, 95% CI: 0.4-0.9, p=0.0111 for stroke/TIA; HR=0.4, 95% CI: 0.3-0.6, p<0.0001 for heart failure; HR=0.3, 95% CI:0.2-0.5, p<0.0001 for death). CONCLUSIONS: Catheter ablation of AF was associated with very significant reductions in mortality, stroke/TIA, and heart failure compared with a matched general AF population and a matched population who underwent cardioversion. Potential confounding of outcomes was minimized by very tight cohort matching.

Stroke rates before and after ablation of atrial fibrillation and in propensity-matched controls in the UK.

BACKGROUND: We sought to determine whether catheter ablation of atrial fibrillation (AF) is associated with reduced occurrence of ischemic cerebrovascular events. METHODS AND RESULTS: Using routinely collected hospital data, ablation patients were matched to two control cohorts via direct and propensity score matching. A total of 4,991 ablation patients were matched 1:1 to general AF controls with no ablation, and 5,407 ablation patients were similarly matched to controls who underwent cardioversion. Yearly rates of ischemic stroke or transient ischemic attack (stroke/TIA) before and after an index date were compared between cohorts. Index date was defined as the first ablation, the first cardioversion, or the second AF event in the general AF cohort. Matched populations had very similar demographic and comorbidity profiles, including nearly identical CHA2DS2-VASc risk distribution (p-values 0.6948 and 0.8152 vs general AF and cardioversion cohorts). Statistical models of stroke/TIA risk in the preindex period showed no difference in annual event rates between cohorts (mean±standard error 0.30% ± 0.08% ablation vs 0.28% ± 0.07% general AF, p=0.8292; 0.37% ± 0.09% ablation vs 0.42% ± 0.08% cardioversion, p=0.5198). Postindex models showed significantly lower annual rates of stroke/TIA in ablation patients compared with each control group over 5 years (0.64% ± 0.11% ablation vs 1.84% ± 0.23% general AF, p<0.0001; 0.82% ± 0.15% ablation vs 1.37% ± 0.18% cardioversion, p=0.0222). CONCLUSION: Matching resulted in cohorts having the same baseline risks and rates of ischemic cerebrovascular events. After the index date, there were significantly lower yearly event rates in the ablation cohort. These results suggest the divergence in outcome rates stems from variance in the treatment pathways beginning at the index date.