Do practice gaps exist in evidence-based medication prescription at hospital discharge in patients undergoing coronary artery bypass surgery & coronary angioplasty?

BACKGROUND & OBJECTIVES: Prescription patterns of guideline-directed medical therapy (GDMT) after coronary artery bypass surgery [coronary artery bypass graft (CABG)] and percutaneous coronary intervention (PCI) at hospital discharge are often not optimal. In view of scarce data from the developing world, a retrospective analysis of medication advice to patients following CABG and PCI was conducted. METHODS: Records of 5948 patients (post-PCI: 5152, post-CABG: 796) who underwent revascularization from 2010 to 2014 at a single tertiary care centre in north India were analyzed. RESULTS: While age and gender distributions were similar, diabetes and stable angina were more frequent in CABG group. Prescription rates for aspirin 100 per cent versus 98.2 per cent were similar, while beta-blockers (BBs, 95.2 vs 90%), statins (98.2 vs 91.6%), angiotensin-converting enzyme inhibitors (89.4 vs 41.4%), nitrates (51.2 vs 1.1%) and calcium channel blockers (6.6 vs 1.6%) were more frequently prescribed following PCI. Despite similar baseline left ventricular ejection fraction (48.1 vs 51.1%), diuretics were prescribed almost universally post-CABG (98.2 vs 10.9%, P<0.001). Nearly all (94.4%) post-CABG patients received a prescription for clopidogrel. Patients undergoing PCI were much more likely to receive higher statin dose; 40-80 mg atorvastatin (72 vs <1%, P<0.001) and a higher dose of BB. INTERPRETATION & CONCLUSIONS: Significant differences in prescription of GDMT between PCI and CABG patients existed at hospital discharge. A substantial proportion of post-CABG patients did not receive BB and/or statins. These patients were also less likely to receive high-dose statin or optimal BB dose and more likely to routinely receive clopidogrel and diuretics. Such deviations from GDMT need to be rectified to improve quality of cardiac care after coronary revascularization.