Healthcare IT

Background:

Coronary artery disease (CAD) is a very common cause of morbidity and is the leading cause of death in adults, accounting for ~one-third of all deaths in subjects over age 35. Although catheter coronary angiography (CCA) is the gold standard in the diagnosis and management of CAD, coronary CT angiography (CCTA), a non-invasive test is recommended by recent evidence for low-medium pretest probability for CAD.

Methods

1320 subjects were screened and a Cardiac risk profiling were done in a 6 months study period in 2016. Traditional risk factors for CAD like hypertension, dyslipidemia, diabetes, obesity, smoking, family history of CAD etc. were mapped out. A weighted average risk stratification tool was devised to stratify suspected CAD groups and to thereby clinically corroborate using CT Angiogram. 477(36%) underwent 320 slice Coronary CT Angiogram. Both, asymptomatic and diseased groups underwent the CCTA. Patients were classified as (a) normal (no calcific or soft plaque), (b) thick plaque & moderate CAD (<50% stenosis), (c) obstructive coronary disease (>50% stenosis).

Results

316(66%) were males and 161(33%) were females. Mean age was 55.6+/- 8.3 years.

176( 37%) had hypertension, 150( 31%) had dyslipidemia, 125( 26%) had diabetes mellitus, 83( 17%) had obesity/overweight( BMI>25), 15(3%) had family history of CAD and 14(3%) as smoking as co-morbid conditions in these mutually non-exclusive data groups of 477 cases who underwent CCTA.

Baseline clinical characterstics were chest pain/angina-177( 37%) of which atypical chest pain contributed 54( 30%). 78(16%) had shortness of breath, 24(5%) had palpitation, 55(12%) had a positive/borderline Treadmill test. ECHO ( EF<40) was found in 9(2%) of the cases. 85(18%) cases were asymptomatic.

199( 42%) cases were found to have normal coronary arteries on CCTA, 277(58%) of the subjects had an abnormal CT angiogram findings of which 75(15.7%) were status post Percutaneous Interventions/Coronary Artery bypass surgeries reviewed for graft patency. Out of these 75 cases, 28(37%) had graft or the native vessel occlusion after a median follow up of 8.2 years after the CABG/PTCA by this CCTA. 

3 risk factors( hypertension, diabetes & dyslipidemia) present in 39(95%) cases had abnormal CT Angiogram of the total 41 cases. 2 risk factors(hypertension, diabetes or dyslipidemia) resulted in 87(31.3%) cases of 278 abnormal CT Angio findings arm versus 62(31.1%) of 199 normal CT Angio findings.

58(12%) of the subjects who had a CCTA were less than 40 years old of which 18( 31%) had a CAD, 12( 66%) were soft and thick plaque whereas 6( 33%) had obstructive coronary artery disease (>50% stenosis).  

Coronary Calcium score zero was found in 219(46%) of the 477 cases. Coronary Calcium score(>100) in 67(14%) in the abnormal CT angio arm versus 3(0.6%) in normal CT Angio arm. CAC score to predict CAD in my study was 39% sensitivity, 98.5% specificity with a positive predictive value of 95.7% and a negative predictive value of 64.9%.

Significantly obstructive triple vessel disease was noted in 10 (3.6%) of total cases. Of the total 278 abnormal CT Angio, Mild CAD was noted in 107(38.5%), Thick plaque ( <50% stenosis) noted in 59(21.2%), obstructive CAD(>50% stenosis) were noted in 98(35.3%) cases. Double vessel disease was seen in 112 (40.3%) cases and single vessel disease was seen in 78 (28%)

Congenital Heart Disease( ASD/VSD) were found in 7(1%) of the cases. Left Ventricular Hypertrophy in 31(6%) of the cases as other CCTA findings. 

Conclusion:

Risk profiling and stratification may be a valuable tool which may correlate with CT angio findings. One third of Coronary artery disease found in age groups of <40 years from this study, a decade/few decades early shift of cardiac events in population, is alarming.