Vascular Risk Prediction
Profiling tools for subjects at risk for a first, unheralded vascular disease
An update from the Taskforce on Vascular Risk Prediction
Michel Romanens, 05.05.2007
Vascular Risk Prediction
Principle Goal of the Taskforce
Improve risk prediction in originally healthy people, in whom a high risk derived from the major independent cardiovascular risk factors is not evident
Michel Romanens, 05.05.2007
Vascular Risk Prediction
Guidelines 2005: ....
AGLA / Executive Committee SGK Secondary prevention:
IntensificationPrimary Prevention:
Discuss Guidelines of ESC and IAS Try to reach common guidelines in the next years
Michel Romanens, 05.05.2007
Vascular Risk Prediction
3 Questions
IAS-AGLA or EAS-SCORE or FRAMINGHAM as a first measure ?
PLAQUE or ISCHEMIA or hsCRP to further stratify risk ?
BAYES or ROC or ODDS to estimate the value of a test ?
Michel Romanens, 05.05.2007
Vascular Risk Prediction
3 levels of risk
PROCAM CORDICARE I Germany OLTEN COHORTMen Only Men and WomenAge 35-65 Age 45+N=5389 N=914
RISK Distribution Events Distribution Events
High 8% 33% 2% ?Intermediate 15% 33% 11% ?Low 77% 33% 87% ?
Michel Romanens, 05.05.2007
Vascular Risk Prediction
3 possible strategies
A down-calibrate definition of high risk from 20% to 15%?general practitionars might be even more confused than they are already now
B treat virtually everybodies cholesterol in intermediate risk
C further risk stratify with new tools in intermediate risk
Michel Romanens, 05.05.2007
Vascular Risk Prediction
IAS-AGLA or EAS-SCORE / Strategy B
CORIDCARE I
Indication forLDL or total Cholesterolloweringintervention
Michel Romanens, 05.05.2007
Vascular Risk PredictionIAS-AGLA or EAS-SCORE
Strategy B: treat them all in intermediate risk defined by IAS-AGLA
IAS-AGLA Intermediate Risk CORDICARE I = 11% of 914 subjects > 45 years10 year risk for AMI is about 15% on average Year 2005: 410251 subjects in CH > 40 years at intermediate riskOf these, 91% would be treated with statins (CORDICARE I)61538 AMI would occur in 10 years (30769 deaths)Statins lower risk by 30%Risk would be reduced from 15% to 11% with statinsAbsolute Risk reduction 16800 AMI (8400 deaths)Relative Risk reduction 27%NNT 24
Michel Romanens, 05.05.2007
Vascular Risk PredictionIAS-AGLA or EAS-SCORE
Strategy C: further risk stratify intermediate risk defined by IAS-AGLA
Ca-Scoring ?
Ultrasound Plaque Imaging ?
hsCRP?
Michel Romanens, 05.05.2007 /
Vascular Risk PredictionStrategies to assess the value of a test
A ROC analysisB ODD ratios, relative risk, correction for co-factorsC Bayes Posttest Calculator
Michel Romanens, 05.05.2007 /
Vascular Risk PredictionStrategies to assess the value of a test
Michel Romanens, 05.05.2007 /
Vascular Risk PredictionROC, ODD, or BAYES
Nancy Cook statements:
„Indeed, if improvement in the ROC statistic was used as the criterion for model inclusion, then neither LDL-C, HDL-C, nor total cholesterol would have been included in risk models after accounting for age, blood pressure, and smoking.”
“The Bayes information …is related to the posterior probability that the model is correct, and is a conservative criterion for model selection.”
Michel Romanens, 05.05.2007 / Wald NJ, Law MR. BMJ. 2003;326:1419
Vascular Risk PredictionROC, ODD, or BAYES
Single Risk Factor Testing
Significant overlap between diseased and non diseased
Michel Romanens, 05.05.2007 / Hypertension. 2006;48:392-396.
Vascular Risk PredictionIAS-AGLA or EAS-SCORE
Strategy C: further risk stratify intermediate risk defined by IAS-AGLA: relative risk for various risk factors in middle aged subjects
Hypertension
LDL>4.1 Men
LDL>4.1 Women
Nicotine Men
Nicotine Women
Diabetes Men
Diabetes Women
ARIC Study
Michel Romanens, 05.05.2007
Vascular Risk PredictionBayes Posttest Risk as a – third – solution between ROC and ODDs ?
Look for practicle solutions on www.scopri.ch
SE = SensitivitySP = SpecificityPV = prevalence or pretest probabilityPTP = posttest probability
PTP pos PV × SE / PV × SE + (1 – PV) × (1 – SP) PTP neg PV × (1 – SE) / PV × (1 – SE) + SP × (1 – PV)
Michel Romanens, 05.05.2007
Vascular Risk PredictionBayes Posttest Riskwith 95% CI
Using
Coronary calciumpercentiles
95% CI by Newcombe
Michel Romanens, 05.05.2007
Vascular Risk PredictionBayes Posttest Riskwith 95% CI
Michel Romanens, 05.05.2007
Vascular Risk PredictionBayes Posttest Riskwith 95% CI
http://scopri.ch/posttestcalculators1.html
Michel Romanens, 05.05.2007
Vascular Risk PredictionFuture themes of the taskforce www.taskforce.atherosclerosisimaging.ch
Which emerging imaging test should be ideally used in Switzerland?Are sequential posttest-calculations an issue in risk prediction ? Who should do atherosclerosis imaging tests (accreditation)?Does atherosclerosis imaging convince patients more than verbal communication, that a treatment is necessary?For which test should there be reimbursement and how can that be achieved?What is the cost-efficiency issues of emerging imaging tests?What is the risk-benefit ratio of calcium scoring in intermediate risk subjects in view of the radiation burden per scan (1 mSv).…..
Michel Romanens, 06.05.2006
Vascular Risk Prediction
An Update of the Taskforce
Taskforce
Founding Members in 2005Darioli RogerRomanens Michel
Scientific CoordinatorRomanens Michel
Michel Romanens, 05.05.2007
Vascular Risk PredictionSummary and Future Directions
Proposition: in God we trust, the others must bring numbers
Let us do the COCA study (5 year outcome of coronary calcifications and carotid total plaque area from a real life experience)
It is designed to produce numbers on outcome, since practice based algorithms may be more useful than population wide epidemiological testing in the future
Michel Romanens, 05.05.2007
Vascular Risk PredictionSummary and Future Directions
Goal of the taskforce: improve risk prediction in originally healthy subjects, and : several publications are underway ….
IAS-AGLA or EAS-SCORE: rather IAS-AGLA
Calcium scoring passes the hardliner test (ROC analysis)
Bayes Posttest Risk Calculators are useful
Many themes are open to debate within the TaskforceCheck on www.taskforce.atherosclerosisimaging.ch
Michel Romanens, 05.05.2007
Vascular Risk Prediction
The presentation is open for discussion