Background: Complete following existing guidelines for management of acute coronary syndrome (ACS) is known to be associated with better outcomes. Partly this is explained by lesser adherence to recommendations in high risk patients. Aim of our study was to assess relationship between degree of following current guidelines and in hospital outcomes independently from initial assessment of risk.
Methods: Each key recommendation from guidelines issued between 2008 and 2011 (13 for STE ACS, 12 for NSTE ACS) was given weight of 1. Sum of these units constituted index of guideline adherence (IGA). IGA was retrospectively calculated for 1656 patients included in Russian independent ACS registry RECORD-2 (7 hospitals, duration 04.2009 to 04.2011). The patients were divided into 2 groups according to quartiles of IGA distribution: 1) low adherence group (quartiles I-II); 2) high adherence group (quartiles III-IV).
Results: In low adherence compared with high adherence group there were significantly more patients more or equal 65 years (=0.0007), with chronic heart failure [CHF] (<0.0001), previous stroke (<0.0001), atrial fibrillation [AF] (=0.0002), Killip class more or equal II (=0.0065), high risk of death by GRACE score (=0.035). Inhospital mortality was 9.3 and 2.4% in low and high adherence group, respectively (p<0.0001). The following independent predictors of inhospital death were identified: IGA quartiles I-II (odds ratio [OR] 4.0; 95% confidence interval [CI] 2.3-7.1; <0.0001), high GRACE score (OR 3.3; 95% CI 1.8-6.0; <0.0001), admission systolic BP less or equal 100 mm Hg (OR 3.1; 95% CI 1.8-5.4; <0.0001), admission serum glucose more or equal 8 mmol/l (OR 2.9; 95% CI 1.8-4.7; <0.0001), age more or equal 65 years (OR 2.3; 95% CI 1.3-4.0; =0.005), ST elevation more or equal 1 mm on first ECG (OR 1.7; 95% CI 1.1-2.5; =0.013). From groups with low and high adherence to guidelines we selected pairs of patients (n=588) with similar (or close) age, type of ACS, GRACE score, Killip class, presence of other important risk factors (CHF, AF, previous stroke), and formed 2 equal subgroups without significant differences in important demographic, anamnestic, clinical and laboratory data. Hospital mortality was 7.8 and 2.7% in low and high adherence subgroup, respectively (p<0.0001).
Conclusions: In RECORD-2 ACS registry low adherence to guidelines was more frequent among high risk patients and was independent predictor of inhospital death. Association between degree of guidelines adherence and outcomes persisted after equalizing groups by some factors of risk of mortality.