Dr.Ravi PrakashModerator- Dr Roopa Salwan 13-04-12
INTRODUCTIONCAC Scoring - in asymptomatic pt. CAD burden CV risk prediction - in symptomatic pt. high sensitivity and –ve predictive value to exclude CAD.
ACC/AHA GUIDELINE– CAC scoring (CACs) as a filter for coronary angiography in atypical ACS. CAC s –> as binary test CAC+ve=further test considered. CAC –ve=no further test required.
Recently question mark raised - in population of high pre test risk of CAD - incremental prognostic value of score -significant incidence of CAD in pt. having zero CACs.
AIM OF STUDYTo describe the prevalence and severity of CAD in relation to prognosis in - symptomatic patients -without known CAD - without coronary artery alciﬁcation - undergoing CCTA
METHODThe CONFIRM registry (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) international, multicenter, observational registry collecting clinical, procedural, and follow-up data on patients who underwent 64-detector row CCTA between 2005 and 2009 at 12 centers in 6 countries(Canada, Germany, Italy, Korea, Switzerland, and United States)
Symptomatic patients who underwent concomitant CAC scoring and CCTA were included. Individuals with known CAD were excluded. CAC s with Agatston method 1 130-199 HU 2 200-299 HU 3 300-399HU 4 >400HU
Lesion quantification LESION LUMINAL CLINICAL GRADE STENOSIS SIGNIFICANCE NONE 0% MILD 1-49% NON OBSTRUCTIVE MODERA 50-69% OBSTRUCTIVE TE SEVERE > 70% SEVERELY OBSTRUCTIVE
FOLLOW UP AND OUTCOMEEND POINTS Primary- Death due to any cause Secondary- Consisting of -all-cause mortality, -nonfatal MI, and -coronary revascularizations done 90 days after CCTA.
RESULTS 27125 Patients screened 10,037 Patients selected (symptomatic, without known CAD, undergoing CAC scoring and CCTA)
PROFILE OF STUDY GROUP Mean age =57 Male =56 % Among 10,037 pt. 51% has CAC score of 0. - young - female - low CV risk
Among CAC score=0 group 13% have non obstructive CAD 3.5% have obstructive CAD 1.4% have severe obstructive CAD
In group of obstructive CAD and CACs = 0 82% have SVD 12% have DVD 6% have TVD 0.3% have LMD
For the detection of any stenosis> 50% on CCTA, the presence of measurable CAC on calcium scoring demonstrated a sensitivity of 89%, speciﬁcity of 59%, negative predictive value of 96%, and positive predictive value of 29%. When using a threshold of 70% stenosis for obstructive CAD, a CAC score> 0 demonstrated a sensitivity, speciﬁcity, negative predictive value and positive predictive value of 92%, 55%, 99%, and 16%, respectively.
FOLLOW UP During a median follow-up of 2.1 years, patients with any obstructive CAD by CCTA experienced a signiﬁcantly increased rate of all-cause mortality . When restricted to individuals with a CAC score of 0, there was no difference in all-cause mortality despite the presence of non obstructive or obstructive CAD
FOLLOW UP FOR SECONDARY ENDPOINT Among the 8,907 patients with complete follow-up for the secondary endpoints of coronary revascularization and MI, patients with evidence of obstructive CAD had significantly increased rates of early coronary revascularization, both among patients with and without coronary artery calciﬁcation.
COMPARATIVE PROGNOSTIC VALUE OF CLINICAL VARIABLES, CACSCORING AND CCTA. Independent predictor of adverse events Increasing CAC scores, The presence of nonobstructive CAD, Any stenosis >50%, and the number of coronary territories with 50% stenosis.
DISCUSSION Absence of calcification decreases the likelihood Of CAD ,but does not exclude it. Rate of obstructive CAD in person with zero calcification varies between 7 – 38% Pt. with CACs=0 and obstructive CAD do not show increased mortality due to predominent SVD.
LIMITATIONS OF STUDY1.Deﬁnition of CAD was made using CCTA, the possibility of false-positive and false-negative CCTA ﬁndings exists.2. Patients diagnosed with obstructive CAD on CCTA are more likely to undergo PCI/CABG, especially in early days.3. Differences in the application of medical therapies after CCTA were not assessed4.Individual plaque character was not studied.
CONCLUSION1.Absence of calcification decreases the likelihood Of CAD but does not exclude it. 2. Among patients without CAC, the presence of stenosis of > 50% is predictive of increased rates of late coronary revascularizations and nonfatal MIs during an intermediate-term follow-up period.3. CAC scoring performed at the time of CCTA does not appear to offer signiﬁcant incremental prognostic information