Category Archives: cardiac testing

Screening echocardiograms not beneficial

Clinical Question

Does screening for heart disease with echocardiography decrease mortality, myocardial infarction risk, or stroke risk?

Bottom Line

Population-based screening for heart disease or valve disease with echocardiography will identify cardiac pathology in patients but does not decrease mortality, myocardial infarction risk, or stroke risk. (LOE = 1b)

Reference

Lindekleiv H, Løchen ML, Mathiesen EB, Njølstad I, Wilsgaard T, Schirmer H. Echocardiographic screening of the general population and long-term survival. A randomized clinical study. JAMA Intern Med 2013;173(17):1592-1598.

Study Design: Randomized controlled trial (non-blinded)
Funding: Unknown/not stated
Setting: Population-based
Allocation: Uncertain

Synopsis

In 1994 and 1995 Norwegian researchers enrolled 6861 middle-aged (average age = 60 years) inhabitants of a single city (Tromsø). The participants were randomly assigned, concealed allocation unknown, to a one-time screening for heart disease using 2-dimensional echocardiography or to no screening. The screening and control groups were both all white and evenly split by gender. Approximately 12% of patients self-reported coronary heart disease, 59% had hypertension (though only 13.5% were treated with medication), 32% smoked, and only 4% had diabetes. Screening identified 7.6% of patients with cardiac or valvular conditions and were treated. Over 15 years of follow-up, 26.9% of the participants in the screening group died as compared with 27.6% in the control group (N.S.). Similarly, there was no effect of screening on rates of sudden death, mortality from heart disease, or incidence of fatal and nonfatal myocardial infarction and stroke.

Allen F. Shaughnessy, PharmD, MMedEd
Professor of Family Medicine
Tufts University
Boston, MA

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Routine stress testing after negative Troponin tests seldom helpful

Clinical question: What is the diagnostic yield of performing routine stress testing in patients who have tested negative for acute coronary artery syndrome?

Bottom Line:  Fewer than 1% of patients who present to the ER with acute chest pain and then undergo routine provocative cardiac testing after 2 sets of negative serum troponin results are likely to benefit from angioplasty (American Heart Association [AHA] class I or IIa). False-positive results will be common.(True positive rate 51.2%) (LOE = 2b)

Reference

Hermann LK, Newman DH, Pleasant WA, et al. Yield of routine cardiac testing among patients in an emergency department-based chest pain unit. JAMA Intern Med 2013; 173(12):1128-1133.

Study Design: Cohort (retrospective)

Funding: Self-funded or unfunded

Setting: Emergency department

Allocation: Unknown

Synopsis: The AHA recommends provocative testing (eg, stress testing) in patients with acute chest pain who have negative biomarker results, with the idea that it will identify patients who may benefit from revascularization. The researchers conducting this study identified all patients (N = 4181) without previously identified coronary artery disease who presented to an emergency department over a 6-year period. All included patients had been ruled out for acute coronary syndrome and then had exercise stress testing (n = 512) or myocardial perfusion imaging (n = 3669) while still in the emergency department. Of these patients, 470 (11.2%) had inducible myocardial ischemia. Most were managed medically, but 26.2% of them were deemed to require coronary angiography to determine whether they had obstructive disease that would benefit from revascularization. Of this group, a total of 63 had obstructive disease, but only 28 patients had disease that would benefit from revascularization (AHA class I or IIa). As a result, the true positive rate was only 51.2% for patients undergoing provocative testing and subsequent angiography. Only 0.7% of patients who underwent provocative testing would have benefited from intervention, and an equal percentage had obstructive disease that would have been harmed by catheterization (eg, AHA class III).

Allen F. Shaughnessy, PharmD, MMedEd
Professor of Family Medicine
Tufts University
Boston, MA