Background/Purpose: Most cardiovascular (CV) risk calculators including the Framingham risk score (FRS) and American College of Cardiology (ACC) / American Heart Association (AHA) risk score underestimate CV risk in patients with chronic inflammatory diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and sarcoidosis. It is unclear how these scores perform in estimation of CV risk in patients with SSc.

Methods: Medical records of patients in a geographically well-defined area were reviewed to identify incident cases of SSc (defined by physician diagnosis) from Jan 1, 1980 to Dec 31, 2016. Fulfillment of the 1980 and 2013 SSc classification criteria was ascertained. Cardiovascular disease (CVD) events including coronary artery disease (CAD), congestive heart failure (CHF), cerebrovascular disease (transient ischemic attacks and cerebrovascular accidents), and peripheral arterial disease (PAD) were abstracted. The 10 year general FRS for CVD was calculated and the office-based 10 year FRS, which does not include laboratory values, was used when lipid values were unavailable. The ACC/AHA atherosclerotic CVD (ASCVD) pooled risk score was also calculated using the ACC/AHA risk calculator. Patients were followed until death, migration from Olmsted County or June 30, 2017. Observed follow-up was truncated at 10 years after SSc incidence. For patients with < 10 years of follow-up, the predicted risk for CVD was adjusted proportionately. The standardized incidence ratio (SIR) was estimated as the ratio of the predicted and observed numbers of CVD events.

Results: In order to apply FRS to this cohort of 78 patients with incident SSc, 21 cases were excluded to fit FRS age limits (30-74 years) as were 7 patients with prior CVD; therefore data was available in 44 of 50 cases. The mean FRS was 7.1% (SD 5.2%). Among SSc cases, 2.2 CVD events were predicted and 9 CVD events observed, for a SIR of 4.16 (95% CI 2.16 to 7.99, p< 0.001). Only subjects aged 40 to 79 years were included in the ACC/AHA risk calculator; two patients with prior myocardial infarction or stroke were excluded. Because of missing data on lipids, the ACC/AHA risk score could only be calculated in 22 out of the remaining 42 SSc cases. The mean ACC/AHA risk score was 8.9% (SD 7.8%). The predicted CVD events were 1.2 and 7 CV events were observed, corresponding to an SIR of 5.69 (95% CI 2.71 to 11.94, p< 0.001).

Conclusion: This is the first population-based study using comprehensive individual medical record review to investigate the performance of FRS and ACC/AHA risk score among patients with SSc, of which both are strongly underestimating the risk of CVD events by about 4-fold and 5-fold, respectively.  The poor performance of these risk scores in SSc is consistent with their poor performance in other chronic inflammatory conditions such as RA and SLE. While CVD risk calculators are meant to assist the clinician in identifying high risk patients for appropriate preventive strategies, our study suggests that these scoring systems are inadequate and may misclassify high risk patients as low risk, depriving them of preventive CVD interventions. Better CVD risk assessment tools are needed for CVD risk prediction in patients with SSc.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/reliability-of-traditional-cardiovascular-risk-calculators-in-predicting-risk-of-cardiovascular-disease-in-systemic-sclerosis/