Fifteen percent of eligible patients treated for acute coronary syndrome still are not given ACE inhibitors or angiotensin receptor blockers as recommended, according to data from a quality improvement program. The results were published online Feb. 25 in Circulation: Cardiovascular Quality and Outcomes.
Prescription rates for ACE inhibitors and ARBs were lowest among certain patients who are at greatest risk of adverse outcomes if they don’t take the drugs: those who had coronary artery bypass graft (CABG) surgery to treat their ACS and those with a history of renal insufficiency. And the use of ACE inhibitors and ARBs was lower than that of other evidence-based therapies, such as aspirin and beta-blockers.
Dr. Kevin R. Bainey
"Thus, ongoing quality improvement initiatives are still necessary to help ensure appropriate secondary prevention is delivered," said Dr. Kevin R. Bainey and his associates in the Get With The Guidelines–Coronary Artery Disease (GWTG-CAD) program, a quality improvement effort of the American Heart Association that includes a national registry of coronary artery disease hospitalizations.
To obtain current figures on adherence to guidelines regarding medication after ACS, Dr. Bainey and his colleagues reviewed the records of 80,241 patients admitted to 311 hospitals participating in GWTG program in 2005-2009. The researchers included patients who met American College of Cardiology/AHA class I or class IIa criteria for receiving ACE inhibitor or ARB therapy.
A total of 60,847 patients met ACC/AHA class I risk criteria, for whom it is "strongly recommended that an ACE inhibitor or ARB be started and continued indefinitely." Yet, at the end of the study period, only 85% were discharged with an appropriate prescription: 69.8% received an ACE inhibitor prescription, 13.5% received an ARB prescription, and 1.7% received both. Those rates were lower at the beginning of the period.
A total of 19,394 patients met ACC/AHA class IIa risk criteria, for whom "the use of ACE inhibitor or ARB is reasonable and should be initiated." Yet only 69.3% were discharged with an appropriate prescription: 64.7% received an ACE inhibitor prescription, 4.0% received an ARB prescription, and 0.6% received both.
In comparison, 98% of eligible patients were discharged on aspirin and 97% were discharged on beta-blockers, said Dr. Bainey of the Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, and his associates.
Appropriate prescription of ACE inhibitors and ARBs was "strikingly" low in patients who had undergone CABG during the hospitalization; such patients were 50% less likely than were others to receive the drugs, even though they were at much higher risk. This trend has been noted in previous studies and provides "further evidence of a persistent care gap that requires immediate attention," the investigators said (Circ. Cardiovasc. Qual. Outcomes 2014 Feb. 25 [doi:10.1161/circoutcomes.113.000422]).
"Another striking imbalance in ACE/ARB prescription" occurred in patients with a history of renal insufficiency, who were 40% less likely than were others to receive the drugs. It is possible that clinicians are hesitant to prescribe these medications because of concerns about worsening renal failure or potentiating hyperkalemia. But those risks are extremely low, and "current evidence clearly supports the use of renin-angiotensin system (RAS) inhibitor in halting the progression of chronic kidney disease," Dr. Bainey and his associates said.
The use of ACE inhibitors and ARBs has increased substantially over the past decade, coincident with the implementation of quality assurance initiatives such as GWTG-CAD. It was reassuring that this study showed an increase in use early in the study period. But it appears that this increase has plateaued, "which should prompt further hospital quality improvement and continued monitored adherence to secondary prevention guidelines," they added.
GWTG-CAD is an American Heart Association program and is supported in part by Merck/Schering-Plough and Pfizer. Dr. Bainey reported no financial conflicts of interest; his associates reported numerous ties to industry sources.