CT angiography: front line for acute coronary syndromes now?

Coronary angiotomography in patients with acute coronary syndrome without ST elevation

BACKGROUND

In patients presenting with acute coronary syndrome (ACS) current clinical practice guidelines recommend coronary angiography for its study. This study aims to describe the role of coronary tomography (CT) in non-ST-segment elevation acute coronary syndromes (NSTE-ACS).

RESULTS

Patients over 18 years with a diagnosis of NSTE-ACS who did not meet high-risk criteria and consulted the emergency department of our institution were included. A total of 410 patients were included, in 7% of them, the study was not continued due to an elevated calcium score (>400 AU). 27% had no coronary lesions, 38% had non-obstructive coronary disease (plaques <50%), 27% had plaques over 50%, and 8% were not assessable. Of the total patients, 39% underwent coronary angiography, and 22% required percutaneous angioplasty.

CONCLUSIONS

Performing CT in low and moderate-risk NSTE-ACS patients was feasible, avoiding invasive studies in a significant number of patients and providing extensive anatomical information.

Meta-analysis of 40- and 64-MDCT angiography for assessing coronary artery stenosis

OBJECTIVE

The purpose of our study was to assess the diagnostic performance of thin-slice (< or = 0.625 mm) MDCT coronary angiography compared with invasive coronary angiography for the detection of significant (> or = 50%) stenosis.

MATERIALS AND METHODS

Twenty-two articles on 40- and 64-MDCT coronary angiography were included. Sensitivity and specificity were calculated on a per-patient and per-segment basis; in addition, proximal versus distal segments were evaluated. The effect of nonevaluable patients, nonevaluable segments, and disease prevalence on diagnostic performance was assessed.

RESULTS

Pooled sensitivity on a patient level was 97.7% ([95% CI] 96.2-98.7%) and specificity 91.0% (88.5-93.1%). Pooled sensitivity on a segmental level was 90.8% (89.0-92.4%) and specificity 95.7% (95.2-96.1%); for proximal segments, respectively, 94.2% (92.3-95.7%) and 94.1% (93.4-94.8%), and for distal segments 84.8% (81.1-88.0%) and 96.9% (96.4-97.4%). If nonevaluable MDCT investigations were included, the per-patient specificity was reduced from 91.0% to 89.1% (p > 0.05) when allocating excluded patients as having significant coronary artery stenosis, and the sensitivity was reduced from 97.7% to 96.2% (p > 0.05) when allocating excluded patients as not having significant stenosis. The per-patient prevalence of coronary artery stenosis had no significant influence on the sensitivity for detecting significant stenosis.

CONCLUSION

Forty- and 64-MDCT provide good-to-excellent performance in detecting or ruling out significant coronary artery stenosis, with better results for proximal than for distal coronary artery segments.

Coronary computed tomographic angiography for rapid discharge of low-risk patients with potential acute coronary syndromes

STUDY OBJECTIVE

Coronary computed tomographic (CT) angiography has excellent performance characteristics relative to coronary angiography and exercise or pharmacologic stress testing. We hypothesize that coronary CT angiography can identify a cohort of emergency department (ED) patients with a potential acute coronary syndrome who can be safely discharged with a less than 1% risk of 30-day cardiovascular death or nonfatal myocardial infarction.

METHODS

We conducted a prospective cohort study at an urban university hospital ED that enrolled consecutive patients with potential acute coronary syndromes and a low TIMI risk score who presented to the ED with symptoms suggestive of a potential acute coronary syndrome and received a coronary CT angiography. Our intervention was either immediate coronary CT angiography in the ED or after a 9- to 12-hour observation period that included cardiac marker determinations, depending on time of day. The main clinical outcome was 30-day cardiovascular death or nonfatal myocardial infarction.

RESULTS

Five hundred sixty-eight patients with potential acute coronary syndrome were evaluated: 285 of these received coronary CT angiography immediately in the ED and 283 received coronary CT angiography after a brief observation period. Four hundred seventy-six (84%) were discharged home after coronary CT angiography. During the 30-day follow-up period, no patients died of a cardiovascular event (0%; 95% confidence interval [CI] 0% to 0.8%) or sustained a nonfatal myocardial infarction (0%; 95% CI 0 to 0.8%).

CONCLUSION

ED patients with symptoms concerning for a potential acute coronary syndrome with a low TIMI risk score and a nonischemic initial ECG result can be safely discharged home after a negative coronary CT angiography test result.