Comprehensive CVD Management
Decisions about treatment of cardiovascular risk factors are often made in a way that can limit the effectiveness of chosen therapies. Often clinical decision-making is based on treating individual risk factors, rather than considering a more powerful predictor of future cardiac events—overall cardiovascular disease risk.
In a recent article, Sussman et al describe the findings of a study assessing whether clinicians took overall cardiovascular disease risk into account when making treatment decisions about intensifying hypertension treatment in those with elevated blood pressure.1 They also analyzed whether patients' individual risk factors were associated with the therapy or medications prescribed by clinicians.
The Addressing Barriers to Treatment for Hypertension prospective cohort study examined various factors that influenced providers' decisions about blood pressure management. The study included 856 veterans with diabetes and hypertension, who were treated by clinicians from nine Veterans Health Administration (VHA) facilities in three Midwestern states.
For each patient, the researchers assessed whether a clinician intensified blood pressure therapy within three months of the first visit for hypertension. The authors defined intensification of treatment as an increased dosage for a hypertension medication or starting a new therapy medication or switching to an alternative. Data was obtained from surveys of providers and patients after each clinical visit, electronic medical record review, and data from VHA databases.
Aside from overall cardiovascular risk, the researchers examined other factors that might influence treatment decisions, such as comorbidities and number of medications, and clinical uncertainty about home measurements of blood pressure. They also considered whether clinicians might consider blood pressure treatment to be of uncertain benefit due to previous use of several different blood pressure medications.
To assess the clinical implications of failing to make treatment decisions based on overall cardiovascular disease risk, researchers used data from two meta-analyses which calculated the decrease in coronary heart disease risk associated with treating a patient with a new, normal-dose blood pressure medication.2,3
Of the subjects, 159 (19%) had low or medium risk for cardiovascular disease and 324 (38%), were high risk. Forty-four percent or 373 patients had a history of MI or CHF. Results indicated that there were no significant associations between cardiovascular risk and intensification of blood pressure management with an overall risk (OR) (for stepping up blood pressure therapies) of 1.19 for patients with high risk for CVD versus those with low/medium risk (P=0.43). Likewise, the OR for intensification of treatment for subjects with a history of myocardial infarction or congestive heart failure versus those with low/medium risk for cardiovascular disease was 1.18 (P=0.46). The researchers did find that real-world clinical care for intensifying hypertension therapy was more likely to be influenced by high systolic blood pressure and measurement of blood sugar levels or A1C.
Of the 430 patients with complete data, the 10-year predicted rate for a cardiovascular disease event—based on UKPDS scores—was 34.1% for the 235 treatment-intensified patients vs. 30.6% for those who had no increase in dosage or a new prescription. By contrast, the researchers found that decisions about intensifying treatment would have had a greater impact if they had been based on patients' overall heart disease risk or UKPDS scores. If patients had been assessed based on UKPDS scores, the 10-year risk for a cardiovascular disease event rate before intensification would have been 47.5% versus only 14.3% in the group considered low risk, who would have had no changes in dosages or medication.
Basing clinical decisions about intensification of hypertension treatment on overall cardiovascular disease risk rather than individual risk factors could prevent an estimated 38% more cardiac events—without increasing the number of treated patients, according to the authors.
The study suggests that clinicians frequently consider single risk factors rather than overall cardiovascular disease risk when deciding whether or not to intensify hypertension treatment, the researchers noted. Yet guidelines that encourage basing treatment decisions on overall cardiovascular disease risk might be more effective at and efficient for preventing cardiac disease, they concluded.
1. Sussman JB, Zulman DM, Hayward R, et al. Cardiac risk is not associated with hypertension treatment intensification. Am J Manag Care. 2012; 18 (8): 414-420.
2. Law MR, Morris JK, Wald NJ. Use of blood pressure lowering drugs in the prevention of cardiovascular disease: meta-analysis of 147 randomised trials in the context of expectations from prospective epidemiological studies. BMJ. 2009; 338: b1665
3. Wald DS, Law M, Morris JK, Bestwick JP, et al. Combination therapy versus monotherapy in reducing blood pressure: meta-analysis on 11,000 participants from 42 trials. Am J Med. 2009; 122 (3): 290-300.