The deadly double standard (the saga of screening for subclinical atherosclerosis)

Use of coronary artery calcium score and coronary CT angiography to guide cardiovascular prevention and treatment

Currently, cardiovascular risk stratification to guide preventive therapy relies on clinical scores based on cardiovascular risk factors. However, the discriminative power of these scores is relatively modest. The use of coronary artery calcium score (CACS) and coronary CT angiography (CCTA) has surfaced as methods for enhancing the estimation of risk and potentially providing insights for personalized treatment in individual patients. CACS improves overall cardiovascular risk prediction and may be used to improve the yield of statin therapy in primary prevention, and possibly identify patients with a favorable risk/benefit relationship for antiplatelet therapies. CCTA holds promise to guide anti-atherosclerotic therapies and to monitor individual response to these treatments by assessing individual plaque features, quantifying total plaque volume and composition, and assessing peri-coronary adipose tissue. In this review, we aim to summarize current evidence regarding the use of CACS and CCTA for guiding lipid-lowering and antiplatelet therapy and discuss the possibility of using plaque burden and plaque phenotyping to monitor response to anti-atherosclerotic therapies.

Management of Asymptomatic Patients With Positive Coronary Artery Calcium Scans

Background

The widespread availability of the coronary artery calcium scan to diagnose coronary artery atheroma semiquantitatively and its prognostic significance has frequently resulted in a difficult therapeutic decision for physicians caring for asymptomatic patients.

Patients and Risk Factors

Of particular concern are patients over 40 years of age and young adults characterized by multiple cardiovascular risk factors. The correct prognostic interpretation of coronary artery calcium scores and the potential benefits and risks of various therapeutic modalities need to be understood.

Conclusion

This review describes the therapeutic choices available to endocrinologists and provides recommendations for various treatment options.

Adding carotid total plaque area to the Framingham risk score improves cardiovascular risk classification

INTRODUCTION

Cardiovascular events (CE) due to atherosclerosis are preventable. Identification of high-risk patients helps to focus resources on those most likely to benefit from expensive therapy. Atherosclerosis is not considered for patient risk categorization, even though a fraction of CE are predicted by Framingham risk factors. Our objective was to assess the incremental value of combining total plaque area (TPA) with the Framingham risk score (FramSc) using post-test probability (Ptp) in order to categorize risk in patients without CE and identify those at high risk and requiring intensive treatment.

MATERIAL AND METHODS

A descriptive cross-sectional study was performed in the primary care setting in an Argentine population aged 22-90 years without CE. Both FramSc based on body mass index and Ptp-TPA were employed in 2035 patients for risk stratification and the resulting reclassification was compared. Total plaque area was measured with a high-resolution duplex ultrasound scanner.

RESULTS

57% male, 35% hypertensive, 27% hypercholesterolemia, 14% diabetes. 20.1% were low, 28.5% moderate, and 51.5% high risk. When patients were reclassified, 36% of them changed status; 24.1% migrated to a higher and 13.6% to a lower risk level (κ index = 0.360, SE κ = 0.16, p < 0.05, FramSc vs. Ptp-TPA). With this reclassification, 19.3% were low, 18.9% moderate and 61.8% high risk.

CONCLUSIONS

Quantification of Ptp-TPA leads to higher risk estimation than FramSc, suggesting that Ptp-TPA may be more sensitive than FramSc as a screening tool. If our observation is confirmed with a prospective study, this reclassification would improve the long-term benefits related to CE prevention.

Risk and the physics of clinical prediction

The current paradigm of primary prevention in cardiology uses traditional risk factors to estimate future cardiovascular risk. These risk estimates are based on prediction models derived from prospective cohort studies and are incorporated into guideline-based initiation algorithms for commonly used preventive pharmacologic treatments, such as aspirin and statins. However, risk estimates are more accurate for populations of similar patients than they are for any individual patient. It may be hazardous to presume that the point estimate of risk derived from a population model represents the most accurate estimate for a given patient. In this review, we exploit principles derived from physics as a metaphor for the distinction between predictions regarding populations versus patients. We identify the following: (1) predictions of risk are accurate at the level of populations but do not translate directly to patients, (2) perfect accuracy of individual risk estimation is unobtainable even with the addition of multiple novel risk factors, and (3) direct measurement of subclinical disease (screening) affords far greater certainty regarding the personalized treatment of patients, whereas risk estimates often remain uncertain for patients. In conclusion, shifting our focus from prediction of events to detection of disease could improve personalized decision-making and outcomes. We also discuss innovative future strategies for risk estimation and treatment allocation in preventive cardiology.

Issues in prognostication for hospital specialist palliative care doctors and nurses: a qualitative inquiry

BACKGROUND

Patients with advanced life-limiting diseases have high information needs concerning prognosis yet discussions between patients and healthcare professionals are either avoided or inaccurate due to over-optimism. Available prognostic models are problematic. Literature indicates that hospital specialist palliative care professionals are frequently asked to prognosticate, although their experience of prognostication is unknown. Identifying this experience will support the development of prognosis training for hospital specialist palliative care professionals.

AIM

To explore hospital specialist palliative care professionals' experience of prognostication.

RESEARCH QUESTIONS

'How do specialist palliative care team members prognosticate?'; 'How do they view prognostication?'

DESIGN

Qualitative research - focus group interviews.

SETTING/PARTICIPANTS

Three UK hospital specialist palliative care teams. Participants included medical doctors and palliative care nurses. Inclusion/exclusion criteria: member of hospital specialist palliative care team with knowledge and experience of prognostication. Numbers of participants: four hospital specialist palliative medicine consultants, three senior doctors in training, nine clinical nurse specialists.

RESULTS

Two major themes: Difficulties of prognostication; Benefits of prognostication. Eleven sub-themes: Difficulties (Non-malignant disease; Communicating uncertainty; Seeking definitive prognosis; Participants' feelings; Confidence in prognostication; Estimating prognosis; Dealing with reaction of prognosis; Prognostic error); Benefits (Patient informed decision-making prioritizing needs and care; Family-prioritizing commitments; Services accessing funding and services planning patient care).

CONCLUSIONS

Findings highlight lack of evidence to support practice, and identify the complexity and emotional labour involved in prognostication by hospital specialist palliative care team members, and are used to discuss recommendations for further research and practice.

Potential use of coronary artery calcium progression to guide the management of patients at risk for coronary artery disease events

OPINION STATEMENT

Subclinical coronary artery disease (CAD) is widespread and under-diagnosed. Preventive efforts are required to reduce the burden of this disease and its complications. Imaging of coronary artery calcium (CAC) with cardiac computed tomography is highly specific for the diagnosis of subclinical CAD and can also facilitate treatment decisions in preventive cardiology. Indeed, CAC testing has been recommended by the American Heart Association for asymptomatic patients at intermediate risk for future cardiac events (as defined by clinical risk factors) to refine existing risk estimates. However, the optimal follow-up of those patients who have already undergone CAC testing remains unclear, particularly with regards to repeat CAC testing. The existing literature points to two major considerations for the use of CAC progression in the management of subclinical CAD. On one hand, CAC progression has been used as a surrogate marker to test the efficacy of cardiac preventive medications in halting or regressing CAD. To date, study results have been mostly disappointing and CAC progression appears resistant to medications such as statins. On the other hand, however, CAC progression has potential as a clinical indicator of underlying CAD activity. This may facilitate optimization or up-titration of preventive medications by using CAC progression as a marker of subclinical disease activity. We believe that the data, thus far, argues against the use of a CAC progression as a clinical surrogate marker of preventive therapy efficacy. Further studies with non-statin medications and with concomitant outcome data are needed. However, CAC progression has potential for monitoring subclinical CAD in some patients and may facilitate treatment decisions. In this review we will provide recommendations for repeat CAC testing and discuss when repeat CAC testing may be helpful to assess coronary artery disease progression.

The SHAPE guideline: ahead of its time or just in time?

In 2006, a grass roots movement called SHAPE (Screening for Heart Attack Prevention and Education) published a novel practice guideline for cardiovascular screening in the asymptomatic at-risk population. It suggested the use of noninvasive tests for subclinical atherosclerosis in cardiovascular risk assessment to target intensified preventive care to those at highest risk. The SHAPE guideline received much attention but not as much support from the "official" medical societies. However, subsequent studies published since 2006 have now provided strong supportive evidence for the strategy spearheaded by the SHAPE guideline. Indeed, the latest guidelines issued jointly by the American Heart Association and the American College of Cardiology have elevated recommendation levels for noninvasive imaging of subclinical atherosclerosis. This change is widely viewed as a significant step toward the SHAPE guidelines. The background for SHAPE and the evidence behind the recommendation to use coronary artery calcium score measured by computed tomography, carotid intima-media thickness and plaque measured by ultrasound, and ankle-brachial index in cardiovascular risk assessment is reviewed in this article.

The Jupiter study, CRP screening, and aggressive statin therapy-implications for the primary prevention of cardiovascular disease

CRP levels are strong, independent predictors of cardiovascular risk and can enhance risk stratification. Jupiter enrolled 17 802 apparently healthy middle-aged men and women with CRP levels over 2.0 mg/l, and LDL less than 130 mg/dl. They were randomized to receive rosuvastatin 20 mg daily or placebo, and followed for a primary endpoint of nonfatal myocardial infarction, stroke, arterial revascularization, hospitalization for unstable angina, or cardiovascular death for 1.9 years. Rosuvastatin lowered CRP (37%), LDL (50%), nonfatal myocardial infarction (55%), nonfatal stroke (48%), hospitalization and revascularization (47%), all-cause mortality (20%), and benefited women and minority subgroups. Rosuvastatin was tolerated relatively well, with a small rise in physician-reported diabetes. Jupiter data suggest that patients with high levels of CRP should receive statins. Approximately 4.3% of the population satisfies Jupiter inclusion criteria. A review of the assessment of cardiovascular risk is under way at the National Institutes of Health to guide practitioners.

Coronary artery calcium scores: current thinking and clinical applications

Most incident coronary disease occurs in previously asymptomatic individuals who were considered to be at a lower risk by traditional screening methods. There is a definite advantage if these individuals could be reclassified into a higher risk category, thereby impacting disease outcomes favorably. Coronary artery calcium scores have been recognized as an independent marker for adverse prognosis in coronary disease. Multiple population based studies have acknowledged the shortcomings of risk prediction models such as the Framingham risk score or the Procam score. The science behind coronary calcium is discussed briefly followed by a review of current thinking on calcium scores. An attempt has been made to summarize the appropriate indications and use of calcium scores.