Validation of the Framingham General Cardiovascular Risk Score and Pooled Cohort Equations in a Community-Based Population: A Prospective Cohort Study Analysis 2006-2017

Background

The 10-year atherosclerotic cardiovascular disease (ASCVD) risk - as assessed using the Framingham general cardiovascular risk score (FRS-CVD) or pooled cohort equations (PCE) - is commonly used in Western cohorts for the primary prevention of cardiovascular disease (CVD). However, the FRS-CVD and PCE have not been validated in Taiwanese cohorts.

Objectives

We aimed to validate the FRS-CVD and PCE for assessing the 10-year ASCVD risk using a Taiwanese community-based population.

Methods

We extracted patient data from the Landseed Integrated Outreaching Neighborhood Screening registry, a community-based prospective cohort study established in 2006. Cardiovascular events from 2006 to 2017 were determined from electronic medical records. The discriminative power and calibration of the FRS-CVD and PCE were evaluated.

Results

Overall, 5,139 subjects were analyzed; the 10-year follow-up rate was 99.6%. The mean age at baseline was 52.8 ± 13.1 years, and 44.6% of the subjects were male. In total, 430 of 4,631 (9.3%) and 227 of 4,022 (5.6%) of the FRS-CVD- and PCE-like cohorts, respectively, had ASCVD events. The calibration χ2 of the FRS-CVD was 7.0267 (p = 0.6343) in males and 7.8845 (p = 0.5458) in females; the χ2 of PCE was 13.007 (p = 0.1623) in males and 38.785 (p < 0.001) in females. The area under the receiver operating characteristic curve (AUROC) of the FRS-CVD was 0.76 (0.72-0.79) in males and 0.71 (0.67-0.74) in females; the AUROC of PCE was 0.68 (0.62-0.73) in males and 0.61 (0.56-0.67) in females.

Conclusions

Except for PCE in females, the FRS-CVD and PCE provided good calibration and modest discrimination in statin-naïve Taiwanese individuals without prior CVD.

Statin therapy for primary prevention in men: What is the role for coronary artery calcium?

Current cholesterol guidelines for primary prevention of atherosclerotic cardiovascular disease (ASCVD) base statin treatment decisions on multiple risk factor algorithms (e.g., Pooled Cohort Equations [PCEs]). By available PCEs, most older middle-aged men are statin eligible. But several studies cast doubt on predictive accuracy of available PCEs for ASCVD risk assessment. Recent studies suggest that accuracy can be improved by measurement of coronary artery calcium (CAC). This method has the advantage of identifying men at low risk in whom statin therapy can be delayed for several years, provided they are monitored periodically for progression of CAC. Thus, there are two approaches to statin therapy in men ≥ 55 years: first all men could be treated routinely, or second, treatment can be based on the extent of coronary calcium. The latter could allow a sizable fraction of men to avoid treatment for several years or indefinitely. Whether with initial CAC scan or with periodic rescanning, a CAC score ≥ 100 Agatston units is high enough to warrant statin therapy. In otherwise high-risk men (e.g., diabetes, severe hypercholesterolemia, 10-year risk by PCE ≥ 20%), a statin is generally indicated without the need for CAC; but in special cases, CAC measurement may aid in treatment decisions.

Temporal trends in atherosclerotic cardiovascular disease risk among U.S. adults. Analysis of the National Health and Nutrition Examination Survey, 1999-2018

BACKGROUND

Atherosclerotic cardiovascular diseases are a significant cause of disability and mortality. Study of trends in cardiovascular risk at a population level helps understand the overall cardiovascular health and the impact of primary prevention efforts.

AIMS

To assess trends in the estimated 10-year atherosclerotic cardiovascular disease (ASCVD) risk among U.S. adults from 1999-2000 to 2017-18 with no established cardiovascular disease (CVD).

METHODS AND RESULTS

Serial cross-sectional analysis of National Health and Nutrition Examination Survey (NHANES) data from 1999-2000 to 2017-18 (10 cycles), including 24 022 US adults aged 40-79 years with no reported ASCVD. ASCVD risk was assessed using the pooled cohort equations (PCEs). There was a significant temporal decline in the mean 10-year ASCVD risk from 13.5% (95% CI, 12.5-14.4) in 1999-2000 to 11.1% (10.5-11.7) in 2011-12 (Ptrend < 0.001) and to 12.0% (11.3-12.7) in 2017-2018 (overall Ptrend = 0.001), with the mean ASCVD risk score remaining stable from 2013-14 through 2017-2018 (Ptrend = 0.056). A declining trend in ASCVD risk was noted in females, non-Hispanic Blacks and those with income <3 times the poverty threshold with Ptrend of <0.001, 0.002, and 0.007, respectively. Mean total cholesterol and prevalence of smokers showed a downward trend (Ptrend <0.001 for both), whereas type 2 diabetes and mean BMI showed an upward trend (Ptrend < 0.001 for both).

CONCLUSIONS

The 20-year trend of ASCVD risk among NHANES participants 40-79 years, as assessed by the use of PCE, showed a non-linear downward trend from 1999-2000 to 2017-18. The initial and significant decline in estimated ASCVD risk from 1999-2000 to 2011-12 subsequently stabilized, with no significant change from 2013-14 to 2017-18. Mean BMI and prevalence of diabetes mellitus increased while mean serum cholesterol levels and prevalence of smoking declined during the study period. Our findings support invigoration of efforts aimed at prevention of CVD, including primordial prevention of CVD risk factors.

Polygenic risk score improves the accuracy of a clinical risk score for coronary artery disease

BACKGROUND

The value of polygenic risk scores (PRSs) towards improving guideline-recommended clinical risk models for coronary artery disease (CAD) prediction is controversial. Here we examine whether an integrated polygenic risk score improves the prediction of CAD beyond pooled cohort equations.  METHODS: An observation study of 291,305 unrelated White British UK Biobank participants enrolled from 2006 to 2010 was conducted. A case-control sample of 9499 prevalent CAD cases and an equal number of randomly selected controls was used for tuning and integrating of the polygenic risk scores. A separate cohort of 272,307 individuals (with follow-up to 2020) was used to examine the risk prediction performance of pooled cohort equations, integrated polygenic risk score, and PRS-enhanced pooled cohort equation for incident CAD cases. The performance of each model was analyzed by discrimination and risk reclassification using a 7.5% threshold.

RESULTS

In the cohort of 272,307 individuals (mean age, 56.7 years) used to analyze predictive accuracy, there were 7036 incident CAD cases over a 12-year follow-up period. Model discrimination was tested for integrated polygenic risk score, pooled cohort equation, and PRS-enhanced pooled cohort equation with reported C-statistics of 0.640 (95% CI, 0.634-0.646), 0.718 (95% CI, 0.713-0.723), and 0.753 (95% CI, 0.748-0.758), respectively. Risk reclassification for the addition of the integrated polygenic risk score to the pooled cohort equation at a 7.5% risk threshold resulted in a net reclassification improvement of 0.117 (95% CI, 0.102 to 0.129) for cases and - 0.023 (95% CI, - 0.025 to - 0.022) for noncases [overall: 0.093 (95% CI, 0.08 to 0.104)]. For incident CAD cases, this represented 14.2% correctly reclassified to the higher-risk category and 2.6% incorrectly reclassified to the lower-risk category.

CONCLUSIONS

Addition of the integrated polygenic risk score for CAD to the pooled cohort questions improves the predictive accuracy for incident CAD and clinical risk classification in the White British from the UK Biobank. These findings suggest that an integrated polygenic risk score may enhance CAD risk prediction and screening in the White British population.

Burden and predictors of statin use in primary and secondary prevention of atherosclerotic vascular disease in the US: From the National Health and Nutrition Examination Survey 2017-2020

AIM

To assess the current state of statin use, factors associated with nonuse, and estimate the burden of potentially preventable ASCVD events.

METHODS

Using nationally representative data from the 2017-2020 NHANES survey, statin use was assessed in primary prevention groups: high ASCVD risk >=20%, low-density lipoprotein-cholesterol (LDL-C) >= 190 mg/dL, diabetes aged 40-75 years, intermediate ASCVD risk (7.5 to <20%) with >= 1 ASCVD risk enhancer and secondary prevention group: established ASCVD. ASCVD risk was estimated using pooled cohort equations.

RESULTS

We estimated 70 million eligible individuals (2.3 million with LDL-C>=190 mg/dL; 9.4 million with ASCVD>=20%; 15 million with diabetes and age 40-75years; 20 million with intermediate ASCVD risk and >=1 risk enhancers; and 24.6 million with established ASCVD), about 30 million were on statin therapy. The proportion of individuals not on statin therapy was highest in the isolated LDL-C>=190 mg/dl group (92.8%) and those with intermediate ASCVD risk plus enhancers (74.6%) followed by 59.4% with high ASCVD risk, 54.8% with diabetes, and 41.5% of those with established ASCVD groups. Increasing age and those with health insurance were more likely to be on statin therapy in both the primary and secondary prevention categories. Individuals without a routine place of care were less likely to be on statin therapy. A total of 385,000 (high-intensity statin) and 647,000 (moderate-intensity statin) ASCVD events could be prevented if all statin-eligible individuals were treated (and adherent) for primary prevention over a 10-year period.

CONCLUSION

Statin use for primary and secondary prevention of ASCVD remains suboptimal. Bridging the therapeutic gap can prevent approximately one million ASCVD events over the subsequent ten years for the primary prevention group. Social determinants of health such as access to care and healthcare coverage were associated with less statin treatment. Novel interventions to improve statin prescription and adherence are needed.

Association between estimated glomerular filtration rate and 10-year atherosclerotic cardiovascular disease risk among community residents in Shanghai, China

BACKGROUND AND AIMS

The association between the estimated glomerular filtration rate (eGFR) and atherosclerotic cardiovascular disease (ASCVD) risk is unknown. We aimed to evaluate whether eGFR can be used as a predictor in ASCVD risk assessment.

METHODS AND RESULTS

Using baseline data from 28,187 participants from Shanghai Suburban Adult Cohort and Biobank study, we adopted Pooled Cohort Equations (PCEs) and Prediction for ASCVD Risk in China (China-PAR) to estimate 10-year ASCVD risk. Multivariate logistic regression was used to analyze the relationship between 10-year ASCVD risk and eGFR. The receiver operating characteristic (ROC) curve was used to evaluate predictive value of eGFR for 10-year high ASCVD risk. Compared with normal eGFR, both men and women with reduced eGFR had a higher prevalence of ASCVD risk factors. With the decrease of eGFR level, the median of 10-year ASCVD risk gradually increased. For men, the adjusted odds ratios (95% confidence interval (CI)) of 10-year high ASCVD risk by PCEs associated with eGFR (60-74 and <60 mL/min/1.73 m²) were 1.52 (95%CI:1.17-1.99) and 2.51 (95%CI:1.27-4.97). The corresponding result was significant only for eGFR < 60 mL/min/1.73 m², OR of 1.57 (1.14-2.18) for women. Using China-PAR, the adjusted OR of 10-year high risk associated with eGFR < 60 mL/min/1.73 m² was 1.82 (1.40-2.38) in men. ROC indicated that eGFR has a good predictive value for 10-year high ASCVD risk.

CONCLUSION

eGFR may be an important risk factor in predicting and stratifying ASCVD risk. Consideration should be given to integrating eGFR into existing risk assessment tools to improve predictive performance.

Association of Health-Related Quality of Life with Atherosclerotic Cardiovascular Disease: Lifetime Risk Pooling Project

Objective

The Pooled Cohort Equations (PCE) serve as the platform for quantitative risk assessment for atherosclerotic cardiovascular disease (ASCVD). Data are sparse regarding the benefit of adding health-related quality of life (HRQoL) measures to the PCE. We sought to estimate the association of HRQoL with ASCVD events and evaluate the potential utility of adding HRQoL to the PCE in refining quantitative risk assessment for primary prevention decisions.

Methods

Three multi-ethnic longitudinal cohorts were included in the study. HRQoL was measured using the SF-12 physical component summary (PCS) and mental component summary (MCS); higher PCS or MCS scores indicate better HRQoL. We constructed a four-level HRQoL status variable: MCS <50 and PCS <50; MCS <50 and PCS ≥50; MCS ≥50 and PCS <50; MCS ≥50 and PCS ≥50. Harrell's C statistics and net reclassification improvement (NRI) analyses were used to assess the added predictive ability of HRQoL for incident ASCVD.

Results

A total of 9,904 individuals were included in the analysis, of whom 4,743 were in the low risk subgroup (<5% predicted 10-year risk). HRQoL status, PCS and its subscale scores were independent predictors of ASCVD events. HRQoL improved both discrimination (delta C: 0.004, p = 0.05) and reclassification (cNRI: 0.15, p<0.01) modestly when added to PCE; 3% and 6% of individuals with events were correctly reclassified to higher risk in the overall sample and low risk subgroup, respectively.

Conclusion

HRQoL is an independent predictor of ASCVD events, and improves ASCVD risk prediction significantly, though modestly, overall and in low-risk individuals. HRQoL may be a cost-effective risk-enhancing factor for refining quantitative risk assessment for primary prevention decisions.

Prediction of 10-year atherosclerotic cardiovascular disease risk among community residents in Shanghai, China - a comparative analysis of risk algorithms

BACKGROUND AND AIMS

The accuracy of various 10-year atherosclerotic cardiovascular disease (ASCVD) risk models has been debatable. We compared two risk algorithms and explored clustering patterns across different risk stratifications among community residents in Shanghai.

METHODS AND RESULTS

A total of 28,201 residents (aged 40-74 years old) who were free of ASCVD were selected from the Shanghai Survey in China. The 10-year ASCVD risk was estimated by applying the 2013 Pooled Cohort Equations (PCEs) and Prediction for ASCVD Risk in China (China-PAR). The agreement was assessed between PCEs and China-PAR using Cohen's kappa statistics. The mean absolute 10-year ASCVD risk calculated by PCEs and China-PAR was about 10.0% and 6.0%, respectively. PCEs estimated that 44.9% of participants [with a 95% confidence interval (CI):44.0%-45.8%] were at high risk, while China-PAR estimated only 16.7% (95%CI:15.8%-18.0%) were at high risk. In both models, the percentage of high ASCVD risk was higher for participants who were older, men, less educated, current smokers, drinkers and manual workers. Among high-risk individuals, almost all participants (PCEs:90.5%; China-PAR:98.6%) had at least one risk factor; hypertension being the most prevalent. The concordance between PCEs and China-PAR was moderate (kappa:0.428, 95%CI: 0.420-0.434) with a better agreement for women (kappa:0.503,95%CI: 0.493-0.513) than for men (kappa:0.211,95%CI: 0.201-0.221).

CONCLUSION

The proportion of participants with a 10-year ASCVD high risk predicted by China-PAR was lower than the results of the PCEs. The risk stratifications of the two algorithms were inconsistent in terms of demographic and life-behaviour characteristics.

Preventive Cardiology and Risk Assessment: Beyond LDL

PURPOSE OF REVIEW

Risk assessment is the foundational cornerstone for cardiovascular prevention. The goal of this review is to apprise the reader of the latest evidence and guideline-based stepwise method for clinical risk assessment for future atherosclerotic events. We also discuss caveats to the current approach and review future directions including the promise of precision medicine.

RECENT FINDINGS

The most recent cholesterol and prevention guidelines improve upon the widely used pooled cohort equations by incorporating risk-enhancing factors to further personalize risk assessment. For those in whom uncertainty remains, there is mounting evidence for using the coronary calcium score to uncover subclinical disease to either up- or down-classify risk. Although still in its infancy, progress in high-throughput molecular analysis is edging the field closer to more precise risk stratification. Atherosclerosis is the leading cause of global morbidity and mortality. Emphasis on cardiovascular prevention is essential to mitigate the burden of disease. Here, we introduce a "4 + 2" paradigm for approaching preventive cardiology based on recent guidelines. Risk stratification is performed in four steps: qualitative risk approximation to initiate counseling and education, quantitative risk estimation based on a validated model, personalization with risk-enhancing factors, and measurement of coronary artery calcium score in select patients. The two foundational principles of preventive management are to promote a healthy lifestyle in all and to escalate preventive pharmacotherapy based on increasing risk. Shared decision-making remains central throughout this process.

Comparative performance of pooled cohort equations and Framingham risk scores in cardiovascular disease risk classification in a slum setting in Nairobi Kenya

BACKGROUND

Cardiovascular diseases (CVD) cause 18 million deaths annually. Low- and middle-income countries (LMICs) account for 80% of the CVD burden, and the burden is expected to grow in the region in the coming years. Screening for and identification of individuals at high risk for CVD in primary care settings can be accomplished using available CVD risk scores. However, few of these scores have been validated/recalibrated for use in sub-Saharan Africa (SSA).

METHODS

Pooled cohort equations (PCE) and Framingham risk scores for 10-year CVD risk were applied on 1960 men and women aged 40 years and older from the AWI-Gen (Africa, Wits-INDEPTH Partnership for GENomic studies) study 2015. Low, moderate/intermediate or high CVD risk classifications correspond to <10%, 10-20% and >20% chance of developing CVD in 10 years respectively. Agreement between the risk scores was assessed using kappa and correlation coefficients.

RESULTS

High CVD risk was 10.3% in PCE 2013, 0.4% in PCE 2018, 2.9% in Framingham and 3.6% in Framingham non-laboratory scores. Conversely, low CVD risk was 62.2% in PCE 2013 and 95.6% in PCE 2018, 84.0% and 80.1% in Framingham and Framingham non-laboratory scores, respectively. A moderate agreement existed between the Framingham functions (kappa = 0.64, 95% CI 0.59-0.68, correlation, rs = 0.711). There was no agreement between the PCE 2013 and 2018 functions (kappa = 0.05, 95% CI 0.04-0.06).

CONCLUSIONS

Newer cohort-based data is necessary to validate and recalibrate existing CVD risk scores in order to develop appropriate functions for use in SSA.

External validation of pooled cohort equations using systolic blood pressure intervention trial data

Objective

The risk of atherosclerotic cardiovascular disease (ASCVD) is estimated using the American College of Cardiology (ACC)/American Heart Association (AHA) Pooled Cohort Equations (PCEs). However, the accuracy of this tool remains controversial, particularly among patients who are recommended statin therapy according to the ACC/AHA guidelines. We performed external validation of PCEs among patients eligible for statin therapy using data from the systolic blood pressure intervention trial (SPRINT).

Results

Our study included 4057 patients from among the 9361 patients in SPRINT. The mean patient age was 64.5 years, and the median predicted 10-year risks of ASCVD were 17.2% and 12.3% for men and women, respectively. Over a median follow-up of 3.3 years, 133 primary events (including 23 cardiovascular deaths) were noted, whereas 304 events were predicted by the PCEs. The PCEs demonstrated poor calibration (Hosmer–Lemeshow test, p < 0.001) and overestimated the probability consistently. Additionally, they showed moderate discrimination [area under the curve: 0.65 (95% confidence interval, 0.60–0.69)]. This study demonstrates that PCEs might overestimate the risk of ASCVD in patients who are recommended statin therapy.

Convergent validity of the ACC/AHA pooled cohort equations in associating with health-related quality of life among adults in the United States

Background: The potential convergent validity of the pooled cohort risk (PCR) equations in predicting health-related quality of life (HRQOL) has yet to be evaluated, which was this study's purpose. Methods: Data from the 2001-2011 National Health and Nutrition Examination Survey (NHANES) were used (N = 8978 adults, 40-79 years, free of cardiovascular disease at baseline). Calculation of an individual's 10-year risk of a first atherosclerotic cardiovascular disease (ASCVD) event was determined via the PCR equation. The Centers for Disease Control and Prevention (CDC) HRQOL measure was assessed utilizing 4 questions regarding participants' perceived mental and physical health status from the past 30 days. Results: When adjusting for moderate-to-vigorous physical activity (MVPA), obesity, age, gender and race-ethnicity, an ASCVD score of >20% (vs. <20%) was associated with a 0.53-unit (95% CI: 0.34-0.71) higher HRQOL score. A higher HRQOL score indicates a poorer patient perception of their mental and physical health. Conclusion: The observed association between PCR-determined ASCVD-risk scores and HRQOL provides evidence for the convergent validity of the PCR algorithms, indicating that individuals with a higher risk for a first time ASCVD-event may also have an overall worse HRQOL. As such, employing ASCVD risk reduction efforts may be an important strategy in improving an individual's HRQOL.

The 2013 American College of Cardiology/American Heart Association guidelines on treating blood cholesterol and assessing cardiovascular risk: a busy practitioner's guide

The 2013 American College of Cardiology/American Heart Association Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults and Guideline on the Assessment of Cardiovascular Risk were released in mid-November 2013. This article explains the guidelines, the risk equations, and their derivations, and addresses criticisms so that practicing physicians may be more comfortable in using the guidelines and the risk equations to inform patients of their atherosclerotic cardiovascular risk and choices to reduce that risk. The article also addresses patient concerns about statin safety if lifestyle changes have been insufficient to reduce their risk.