Influence of coronary computed tomographic angiography on patient treatment and prognosis in patients with suspected stable angina pectoris

Preventive Management of Nonobstructive CAD After Coronary CT Angiography in the Emergency Department

OBJECTIVES

This study sought to assess medical management of patients found to have nonobstructive coronary artery disease (CAD) on coronary computed tomography angiography (CCTA) performed in the emergency department (ED).

BACKGROUND

Contemporary recognition and management of nonobstructive CAD discovered on CCTA performed in the ED is unknown.

METHODS

Patients undergoing CCTA in the authors' hospital's ED between November 2013 and March 2018 who also received primary care within the authors' health system were studied. All patients with nonobstructive CAD, defined as 1% to 49% maximum luminal stenosis on CCTA, were included, along with a control group without CAD in a 1 case:1 control fashion. Ten-year atherosclerotic cardiovascular disease (ASCVD) risk prior to CCTA was estimated using the Pooled Cohort Equations. Management changes were recorded until 6 months after CCTA. Multivariate logistic regression tested the association between CCTA result and follow-up statin prescription, adjusting for cardiovascular risk factors and baseline statin use.

RESULTS

The cohort included 510 patients with nonobstructive CAD and 510 controls. Prevalence of statin prescription increased from 38.8% to 56.1% among patients with nonobstructive CAD (p < 0.001) and 18.0% to 20.4% among controls (p = 0.01), representing a 7.1-fold relative difference (95% confidence interval [CI]: 4.4 to 23.0; p < 0.001) in multivariate analysis. However, 30.0% of patients with nonobstructive CAD and ≥20% 10-year ASCVD risk were not prescribed a statin at the end of follow-up. Cardiologist evaluation was independently associated with statin prescription after adjustment for ASCVD risk factors (odds ratio [OR] 4.4; 95% CI: 2.4 to 8.5; p < 0.001). A Coronary Artery Disease Reporting and Data System class 1 to 2 result was associated with lower low-density lipoprotein cholesterol by 12.1 mg/dl at mean 1.9-year follow-up (p < 0.001).

CONCLUSIONS

Incidental subclinical atherosclerosis on CCTA performed in the ED increases the likelihood of statin prescription, but opportunities to improve allocation of indicated preventive therapies remain.

Exercise Electrocardiogram Neither Predicts Nor Excludes Coronary Artery Disease in Women with Low to Intermediate Risk

AIM

The value of exercise electrocardiogram (ExECG) in symptomatic female patients with low to intermediate risk for significant coronary artery disease (CAD) has been under debate for many years, and nondiagnostic or even erroneous test results are frequently encountered. Cardiac-CT may be more appropriate to exclude CAD in women. This study compares the results of ExECGs with those of cardiac-CTs, performed within a time frame of 1 month in an all-comers female chest pain population.

PATIENTS AND METHODS

Five hundred fifty-one consecutive female patients from a patient registry were included. ExECGs were negative in 324 (59%), positive in 14 (3%), and nondiagnostic in 213 (39%) patients. CAD was revealed by cardiac-CT in 57% of the women with negative ExECG. No signs of CAD were present on cardiac-CT in 64% of the women with a positive ExECG. Cardiac-CT showed presence of CAD in 268/551 (49%) patients, of whom 56/268 (21%) was diagnosed with ≥50% stenosis. The ExECG of the latter group was negative in 26 (46%), inconclusive in 29 (52%), and positive in 1 (2%). Considering ≥50% stenosis at cardiac-CT as the reference, sensitivity, specificity, PPV, and NPV of ExECG for the present population were 3.7%, 95.7%, 7.1%, and 91.7%, respectively. Similar diagnostic performance was calculated when considering ≥70% stenosis at cardiac-CT as the reference.

CONCLUSION

ExECG failed to detect CAD in more than half of this cohort and in almost half of women with >50% stenosis at cardiac-CT. Importantly, no CAD was detected by cardiac-CT in 64% of women with a positive ExECG. ExECG is therefore questionable as a diagnostic strategy in women with low-to-intermediate risk of CAD, although prospective studies are warranted to determine whether replacing ExECG by cardiac-CT provides better prognoses.

Nonobstructive Coronary Artery Disease by Coronary CT Angiography Improves Risk Stratification and Allocation of Statin Therapy

OBJECTIVES

This study sought to determine prognostic value of nonobstructive coronary artery disease (CAD) for atherosclerotic cardiovascular disease (ASCVD) events and to determine whether incorporation of this information into the pooled cohort equation reclassifies recommendations for statin therapy as defined by the 2013 guidelines for cholesterol management of the American College of Cardiology and American Heart Association (ACC/AHA).

BACKGROUND

Detection of nonobstructive CAD by coronary computed tomography angiography may improve risk stratification and permit individualized and more appropriate allocation of statin therapy.

METHODS

This study determined the pooled hazard ratio of nonobstructive CAD for ASCVD events from published studies and incorporated this information into the ACC/AHA pooled cohort equation. The study calculated revised sex- and ethnicity-based 10-year ASCVD risk and determined boundaries corresponding to the original 7.5% risk for ASCVD events. It also assessed reclassification for statin eligibility by incorporating the results from meta-analysis to individual patients from a separate cohort.

RESULTS

This study included 2 studies (2,295 subjects; 66% male; prevalence of nonobstructive CAD, 47%; median follow-up, 49 months; 67 ASCVD events). The hazard ratio of nonobstructive CAD for ASCVD events was 3.2 (95% confidence interval: 1.5 to 6.7). Incorporation of this information into the pooled cohort equation resulted in reclassification toward statin eligibility in individuals with nonobstructive CAD, with an original ASCVD score of 3.0% and 5.9% or higher in African-American women and men and a score of 4.4% and 4.6% or higher in Caucasian women and men, respectively. The absence of nonobstructive CAD resulted in reclassification toward statin ineligibility if the original ASCVD score was as 10.0% and 17.9% or lower in African-American women and men and 13.7% and 14.3% or lower in Caucasian women and men, respectively. Reclassification is observed in 14% of patients.

CONCLUSIONS

Detection of nonobstructive CAD by coronary computed tomography angiography improves risk stratification and permits individualized and more appropriate allocation of statin therapy across sex and ethnicity groups.

Different Plaque Composition and Progression in Patients with Stable and Unstable Coronary Syndromes Evaluated by Cardiac CT

Objective. To compare the quantity, subtype, and progression of atherosclerosis by cardiac computed tomography (CT) and intravascular ultrasound (IVUS) in patients with stable (SAP) and unstable angina pectoris or non-ST-elevation myocardial infarction (UAP/n-STEMI). Methods. Forty patients with SAP and 20 with UAP/n-STEMI underwent cardiac CT and angiography with IVUS at baseline and after one year. Atherosclerotic segments were divided into calcified, mixed, or noncalcified subtypes, and significant stenoses were registered. Results. Thirty-two SAP and 15 UAP/n-STEMI patients completed the CT follow-up. At baseline, the number of atherosclerotic segments was higher in UAP/n-STEMI than in SAP (P = 0.039). UAP/n-STEMI patients had more segments with noncalcified plaques (P = 0.0005) whereas SAP patients had more segments with calcified plaques (P = 0.013). The number of segments with significant stenosis did not differ between the groups, but noncalcified plaques more frequently caused significant stenoses in UAP/n-STEMI than in SAP patients (P = 0.0002). After one year the number of segments with atherosclerosis increased in SAP patients (P = 0.0001). The number of atherosclerotic segments remained unchanged in UAP/n-STEMI patients. However, composition was altered as the number of segments with noncalcified plaques decreased (P = 0.018). IVUS data confirmed the CT findings. Conclusion. Quantity, subtype, and progression of atherosclerosis differ between SAP and UAP/n-STEMI patients.

Patients With Suspected Coronary Artery Disease Referred for Examinations in the Era of Coronary Computed Tomography Angiography

Invasive coronary angiography (ICA) is the gold standard in the diagnosis of coronary artery disease (CAD), however, associated with rare but severe complications. Patients with a high pretest risk should be referred directly for ICA, whereas a noninvasive strategy is recommended in the remaining patients. In the setting of a university hospital, we investigated the pattern of diagnostic tests used in daily clinical practice. During a 1-year period, consecutive patients with new symptoms suggestive of CAD and referred for exercise stress test, coronary computed tomography angiography (CCTA), single-photon emission computed tomography (SPECT), or ICA qualified for inclusion. The patients were followed for 1 year, and additional downstream diagnostic tests and need of coronary revascularization were registered. A total of 1,069 patients were included. A noninvasive test was the first examination in 797 patients (75%; exercise stress test in 37, CCTA in 450, and SPECT in 310), whereas 272 (25%) were referred directly to ICA. The ICA group had a significant higher pretest probability for CAD, and the percentage of patients with evidence of significant CAD was 31% (84 of 272 patients), whereas 18% (144 of 797 patients) in the noninvasive group (p <0.0001). In the comparison between CCTA and SPECT, there were no significant differences in downstream testing (16% [72 of 444 patients] vs 17% [53 of 310], p = 0.55), and revascularization rate (20% [14 of 69 patients with positive findings] vs 9% [6 of 67], p = 0.09). In conclusion, a noninvasive diagnostic test was chosen as the first test in 3 of 4 patients. Of the patients referred directly for noninvasive examination, 1/5 had significant CAD, whereas 1/3 of those for invasive examination.

Diagnostic and Therapeutic Usefulness of Coronary Computed Tomography Angiography in Out-Clinic Patients Referred for Chest Pain

Coronary computed tomography angiography (CCTA) is widely used to exclude coronary artery disease (CAD) in patients with low-to-intermediate pretest probability (PTP) of obstructive CAD. The aim of our study was to investigate the reclassification by CCTA and the implications of CCTA results on management because limited studies exist on these subjects; 1,560 patients with chest pain without a history of CAD and with low or intermediate PTP of CAD referred for CCTA from the out-patient clinic were prospectively included. PTP was defined by the Duke Clinical Score as either low (<15%), low-intermediate (15% to 50%), or high-intermediate (50% to 85%). Distribution of CCTA results among the categories of PTP of CAD and the influence of CCTA results on management were analyzed. CCTA revealed obstructive CAD in 7%, 15%, and 23% of cases, in patients with low, low-intermediate, and high-intermediate PTP, respectively; 855 of 1,031 patients (83%) with intermediate PTP of CAD showed no obstructive CAD on CCTA and were consequently reclassified. Management changes after CCTA occurred in 689 patients (44%). In 633 patients (41%), medication was altered and 135 (9%) were referred for invasive coronary angiography. Treatment with statin was initiated in 442 (28%) and stopped in 71 patients (5%). Aspirin was initiated in 192 (12%) and stopped in 139 patients (9%). In conclusion, in a routine clinical cohort, CCTA resulted in reclassification in most patients. Furthermore, our study suggests that the Duke Clinical Score overestimates the probability of obstructive CAD compared with CCTA findings. Finally, CCTA results have implications on patient management, with medication changes in 41% of patients.

Use of cardiac CT and calcium scoring for detecting coronary plaque: implications on prognosis and patient management

Clinicians often use risk factor-based calculators to estimate an individual's risk of developing cardiovascular disease. Non-invasive cardiovascular imaging, particularly coronary artery calcium (CAC) scoring and coronary CT angiography (CTA), allows for direct visualization of coronary atherosclerosis. Among patients without prior coronary artery disease, studies examining CAC and coronary CTA have consistently shown that the presence, extent and severity of coronary atherosclerosis provide additional prognostic information for patients beyond risk factor-based scores alone. This review will highlight the basics of CAC scoring and coronary CTA and discuss their role in impacting patient prognosis and management.

Association of cardiac events with coronary artery disease detected by 64-slice or greater coronary CT angiography: a systematic review and meta-analysis

BACKGROUND

The value of ≥64-slice coronary CT angiography (CCTA) to determine odds of cardiac death or non-fatal myocardial infarction (MI) needs further clarification.

METHODS

We performed a systematic review and meta-analysis using publications reporting events/severity of coronary artery disease (CAD) in patients with suspected CAD undergoing CCTA. Patients were divided into: no CAD, non-obstructive CAD (maximal stenosis <50%), and obstructive CAD (≥50% stenosis). Odds ratios with 95% confidence intervals were calculated using a fixed or random effects model. Heterogeneity was assessed using the I(2) index.

RESULTS

We included thirty-two studies comprising 41,960 patients with 363 all-cause deaths (15.0%), 114 cardiac deaths (4.7%), 342 MI (14.2%), 69 unstable angina (2.8%), and 1527 late revascularizations (63.2%) over 1.96 (SD 0.77) years of follow-up. Cardiac death or MI occurred in 0.04% without, 1.29% with non-obstructive, and 6.53% with obstructive CAD. OR for cardiac death or MI was: 14.92 (95% CI, 6.78 to 32.85) for obstructive CAD, 6.41 (95% CI, 2.44 to 16.84) for non-obstructive CAD versus no CAD, and 3.19 (95% CI, 2.29 to 4.45) for non-obstructive versus obstructive CAD and 6.56 (95% CI, 3.07 to 14.02) for no versus any CAD. Similar trends were noted for all-cause mortality and composite major adverse cardiovascular events.

CONCLUSIONS

Increasing CAD severity detected by CCTA is associated with cardiac death or MI, all-cause mortality, and composite major adverse cardiovascular events. Absence of CAD is associated with very low odds of major adverse events, but non-obstructive disease significantly increases odds of cardiac adverse events in this follow-up period.

Is it prime time for "rapid comprehensive cardiopulmonary imaging" in the emergency department?

Reducing hospital admissions through improved risk stratification of patients with potential acute coronary syndrome represents a critical focus for reducing health care expenditure. Coronary computed tomographic angiography (CTA) has been used with increasing frequency as part of the evaluation of chest pain in the Emergency Department. In the appropriate group of patients at low to intermediate risk CTA appears to be an excellent evaluation strategy, safely and efficiently allowing for the rapid discharge of patients home.