What proportion of patients with chest pain are potentially suitable for computed tomography coronary angiography?

Diagnostic yield of coronary angiography in patients with acute chest pain: role of noninvasive test

OBJECTIVES

This study investigated the diagnostic yield of invasive coronary angiography (CAG) and the impact of noninvasive test (NIV) in patients presented to emergency department (ED) with acute chest pain.

METHODS

Patients 50 years or older who visited ED with acute chest pain and underwent CAG were identified retrospectively. Those with ischemic electrocardiogram, elevated cardiac enzyme, known coronary artery disease (CAD), history of cardiac surgery, renal failure, or allergy to radiocontrast were excluded. Diagnostic yields of CAG to detect significant CAD or differentiate the need for revascularization were analyzed according to whether NIV was performed and its result.

RESULTS

Among the total 375 consecutive patients, significant CAD was observed in 244 (65.1%). Diagnostic yields of CAG were higher in patients who underwent NIV before CAG, but the discriminative effect was modest (59.7% vs 70.7% [P = .026] for detection of CAD; 45.0% vs 50.5% [P = .285] for revascularization). Positive results of NIV were significantly associated with the presence of CAD and the need for revascularization, when compared with patients without NIV or patients with negative results (P < .001, respectively).

CONCLUSION

The diagnostic yield of CAG was only 65% in low- to intermediate-risk ED patients with acute chest pain. Performing of NIV provided only modest improvement in diagnostic yield of CAG. The unexpectedly low diagnostic yield might be attributable to the underuse of NIV and misinterpretation of physicians. We suggest the use of NIV as a gatekeeper to discriminate patients who require CAG and/or revascularization, and for this, better risk stratification and appropriate application of NIV are required.

Evaluation of renal function tests by age and sex to determine emergency department patients' eligibility for cardiac computed tomography

BACKGROUND

Coronary computed tomography angiography (CCTA) can be used for low-risk chest pain patients, but presents a risk of contrast-induced nephropathy.

OBJECTIVE

We compared, by age and sex, the percent of patients who would become ineligible for CCTA based on serum creatinine (SCr) and glomerular filtration rate (GFR) cutoff points.

METHODS

All adult patients who presented to the Emergency Department (ED) with chest pain were screened using their first ED SCr as part of the ROMICAT (Rule Out Myocardial Infarction Using Computer Assisted Tomography) study. This was a secondary analysis of the screening logs of that study. The Modification of Diet in Renal Disease formula was applied to calculate estimated GFR and the percent of patients, by age and sex, meeting commonly applied exclusion criteria using selected SCr and GFR cutoff values. This was our primary outcome.

RESULTS

Of 2398 patients screened, 384 (16%) were excluded for high-risk features or technical limitations of CCTA, leaving 2014 patients who were studied; 56% were male. For all cutoff points of SCr (≥1.3 mg/dL, ≥1.5 mg/dL, ≥1.8 mg/dL), the percent of males excluded significantly exceeded that of females (p < 0.0001 [28.6% males to 18.5% females]; p < 0.0001 [17.4% males to 11.2% females]; p = 0.0004 [10.1% males to 5.8% females], respectively). Conversely, for two of the three cutoff points of GFR (≤60 mL/min/1.73 m(2) and ≤45 mL/min/1.73 m(2)), the percent of females excluded significantly exceeded that of males (p < 0.0001 [33.6% females to 25.4% males] and p = 0.0015 [17.6% males to 12.5% females], respectively).

CONCLUSIONS

The choice of SCr or GFR to screen patients for CCTA selectively excludes either males or females, respectively. Therefore, individual physicians and institutions must understand the impact of both renal function tests and cutoff points when identifying patients who may be eligible for CCTA.