John W. Askew

Application of appropriatenes criteria to stress single photon emission computed tomography sestamibi studies: A comparison of the 2009 revised appropriateness criteria to the 2005 original criteria

BACKGROUND The 2005 appropriate use criteria (AUC) for stress single-photon emission computed tomographic myocardial perfusion imaging (SPECT MPI) were revised in 2009 to reflect changes in published evidence, clinical practice and experience with application of the 2005 AUC. The purpose of this study was to compare the 2009 AUC for SPECT MPI with the original 2005 criteria. METHODS Using the Mayo Rochester Nuclear Cardiology Laboratory database, we retrospectively examined 281 patients who underwent stress SPECT MPI at Mayo Clinic Rochester between May 1, 2005, and May 15, 2005, using the revised 2009 AUC and compared these findings to our previously published results in this same cohort using the 2005 AUC. RESULTS Compared to the 2005 AUC, the 2009 AUC resulted in a highly significant overall change (P < .001) in the classification of appropriateness. The 2009 AUC eliminated unclassified patients, reduced appropriate studies (59.8% vs 63.7%, P = .02), increased studies of uncertain appropriateness (16.0% vs 10.7%, P = .01), and increased inappropriate studies (24.2% vs 14.6%, P < .001). CONCLUSIONS In this cohort of patients undergoing SPECT MPI, compared to our previous study using the original 2005 AUC, the 2009 AUC had a significant impact on the classification of appropriateness. The 2009 AUC eliminated unclassified patients, increased inappropriate studies and increased studies of uncertain appropriateness.

Use of echocardiography in outpatients with chest pain and normal resting electrocardiograms referred to Mayo Clinic Rochester

Objectives To determine how often unnecessary resting echocardiograms that are “not recommended” by clinical practice guidelines are performed in patients with stable chest pain and normal resting electrocardiograms (ECGs). Background There are scant data to indicate how often Class III recommendations are ignored in clinical practice. Patients and Methods We searched electronically all medical records of referral outpatients seen at Mayo Clinic Rochester from January 1, 2010, through December 31, 2013, to identify patients with stable chest pain and known or suspected coronary artery disease who underwent resting echocardiography and had normal resting ECGs and no other indication for echocardiography. Results Of the 15,529 referral outpatients who were evaluated at Mayo Clinic Rochester with chest pain, 3976 (25.6%) had resting echocardiograms. Eight hundred seventy of these 3976 patients (21.9%) had normal resting ECGs. Six hundred nineteen of these 870 patients (71.1%) had other indications for echocardiography. The remaining 251 patients (6.3% of all echocardiograms and 1.6% of all patients) had normal resting ECGs and no other indication for echocardiography. Two hundred thirty‐nine of these 251 patients (95.2%) had normal echocardiograms. Of the 12 abnormal echocardiograms, only 4 led to any change in clinical management. Sixty‐one of these 251 echocardiograms (24.3%) were “preordered” before the provider (physicians, nurses, physician assistants) visit. Conclusion Echocardiograms were performed in 1 in 4 referral outpatients with chest pain seen at Mayo Clinic Rochester. However, only 1 in 16 of these echocardiograms was performed in violation of the class III recommendation in the American College of Cardiology Foundation/American Heart Association guidelines for the management of stable angina. These unnecessary echocardiograms were almost always normal, and had little impact on clinical management. The rate of unnecessary echocardiograms could be decreased by eliminating preordering.

Assessing Clinical Impact of Myocardial Perfusion Studies: Ischemia or Other Prognostic Indicators?

One of the major strengths of nuclear myocardial perfusion imaging (MPI) is the robust prognostic databases from observational studies demonstrating significantly different outcomes in patients with low-risk vs high-risk scans. The severity of the MPI defect can be semi-quantitated using the summed stress score (SSS) and summed difference score (SDS). SSS is more strongly associated with mortality, whereas SDS is the better predictor of subsequent coronary angiography and revascularization. The strength of MPI variables as prognostic indicators decreases when adjusted for prognostically important clinical and stress test variables. Nonetheless, most studies of general patient populations have demonstrated that MPI adds incremental prognostic value to clinical and stress test information. In contrast to these positive results from observational studies, the application of MPI ischemia as a treatment guide in several recent trials (DIAD, WOMEN, COURAGE, BARI 2D, STICH) has largely failed to identify patient subsets with improved outcome. This issue will continue to be investigated in the ongoing PROMISE and ISCHEMIA trials.

EVALUATION OF APICAL POUCHES IN HYPERTROPHIC CARDIOMYOPATHY USING CARDIAC MRI

Presence of an apical pouch in patients with hypertrophic cardiomyopathy (HCM) carries increased cardiovascular risk. Apical pouches are often challenging to visualize by echocardiography, and cardiac magnetic resonance imaging (CMR) may be better suited for identifying apical pouches in HCM. This

EVALUATION OF APICAL SUBTYPE OF HYPERTROPHIC CARDIOMYOPATHY USING CARDIAC MRI WITH GADOLINIUM ENHANCEMENT

Cardiac MRI (CMR) is emerging as a valuable imaging modality in the accurate diagnosis and risk stratification of patients with hypertrophic cardiomyopathy (HCM). CMR is better suited for studying the apical form of HCM due to difficulty imaging the cardiac apex with standard echocardiography. We