Thomas Kottke, MD, MSPH, HealthPartners Institute of Education and Research; Co-investigator, ESCALATES
A few years ago, my fellow researchers and I developed a method to calculate what would happen if all evidence-based care for the prevention and treatment of coronary heart disease and heart failure were delivered. 1
Using deaths prevented or postponed (DPP) as the outcome, we identified three pools of patients who are currently stable:
- patients who apparently do not have heart disease;
- patients who have heart disease that has not damaged their heart muscle; and
- patients who have severe damage to their heart muscle.
We also identified six types of acute events treated by cardiologists: out-of-hospital cardiac arrest, myocardial infarction with ST-segment elevation (STEMI), myocardial infarction without ST-segment elevation (nSTEMI), acute heart failure with low ejection fraction, unstable angina, and heart disease presenting in an ambulatory setting.
Our findings show that primary care physicians can have at least an 81 percent greater impact on a patient’s health by addressing ABCS (aspirin use, blood pressure control, cholesterol and smoking cessation) than a cardiologist can have by improving care for hospitalized patients. I use “at least” because we didn’t include in our calculations primary prevention with aspirin.
Much of the greatest impact on heart health accrues from the fact that treating risk factors (ABCS) prevents multiple diseases, while interventions in hospital do not.
Here’s how we arrived at this conclusion:
We identified clinical trials that documented the efficacy of the various interventions and combined these results with data on population sizes, event rates, mortality rates, risk factor coefficients, and the rates at which each of the interventions is currently being applied. Then we combined all of these data to predict, among other interventions, the impact of improving cardiovascular risk-factor levels vs. providing surgical and medical treatments for patients hospitalized for an acute cardiac event. In other words, we asked, “How did the potential impact of primary care for heart disease risk factors compare to the care that could be delivered to hospitalized patients by heart disease specialists?”
Here’s what we found:
The largest number of preventable deaths occur in a prevalence pool of patients who do not have recognized heart disease. This is because the greatest number of deaths also occurs in that pool.
The vast majority of deaths due to acute events occur as out-of-hospital cardiac arrest, a condition that is survivable only when conditions are perfect. The second largest number of deaths is among patients hospitalized with unstable angina and related conditions, mostly because this group is large and tends to comprise older patients. [ref]Kottke TE, Faith DA, Jordan CO, Pronk NP, Thomas RJ, Capewell S. The comparative effectiveness of heart disease prevention and treatment strategies. Am J Prev Med. 2009;36(1):82-88 e85.[/ref] Both the number of deaths and the number of deaths that might be prevented by improving care for myocardial infarction and heart failure are relatively small. In part because health care is generally very good in U.S. hospitals, but also because these groups are relatively small.
Of course, we need both ambulatory care and hospital care, but the take-home message is that primary care physicians, by providing the ABCS of heart health, have a powerful impact on their patients’ health and well-being. This underscores the importance of EvidenceNOW in supporting primary care practices’ efforts in designing office systems that put cardiac preventive care evidence into action to help patients; and the importance of ESCALATES which will study and identify the strategies and approaches to spreading this evidence that works best.
- Kottke TE, Faith DA, Jordan CO, Pronk NP, Thomas RJ, Capewell S. The comparative effectiveness of heart disease prevention and treatment strategies. Am J Prev Med. 2009;36(1):82-88 e85. ↩