Effect of changes in perfusion defect size during serial regadenoson myocardial perfusion imaging on cardiovascular outcomes in high-risk patients.

BACKGROUND: The prognostic value of single-photon emission computed tomography myocardial perfusion imaging (MPI) is well established. There is a paucity of data on the prognostic value of changes in perfusion defect size (PDS) on serial MPIs. METHODS: From the MPI database at the University of Alabama at Birmingham, consecutive patients who underwent two regadenoson stress MPIs between July 2008 and March 2013 were identified. The MPIs were analyzed side-by-side using an automated software program for presence and change in PDS. Improvement in PDS was defined as a reduction ≥5% of left ventricle. A drop in left ventricular ejection fraction (LVEF) was defined as a decrease ≥5%. The primary outcome was a composite of death, myocardial infarction (MI), and coronary revascularization (CR). RESULTS: There were 698 patients (61 ± 11 years, 53% male, 48% diabetes, 25% prior MI, 49% prior CR) who underwent two regadenoson MPIs within 16 ± 9 months for clinical indications. The primary outcome occurred in 167 (24%) patients (8% death, 9% MI, 15% CR) during 24 ± 16 months of follow-up after the second MPI. The MPIs were normal in both studies in 399 (57%, Group 1), showed improvement in 94 (14%, Group 2, PDS 15% ± 16% vs 28% ± 18%, P < .001) and no change or worsening in 205 patients (29%, Group 3, 28% ± 17% vs 20% ± 17%, P < .001). The best outcomes were seen in Group 1 and the worst in Group 3 (log-rank P < .001). Similar trends were seen for the components of the primary outcome (P = .04 for death, P < .001 for MI, P < .001 for CR). In a Cox-regression model that adjusted for baseline factors including PDS and LVEF on initial MPI, the hazard ratios for primary outcome were 2.0 (P = .02) and 3.9 (P < .001) for Groups 2 and 3 compared to Group 1, respectively. In addition, an LVEF drop ≥5% was independently associated with the primary outcome (HR 1.5, P = .01). CONCLUSION: Changes in PDS and LVEF on serial MPIs provide incremental prognostic information to initial and follow-up MPI findings. Lack of improvement or an increase in PDS and a drop in LVEF identify high-risk patients.

The prognostic value of regadenoson myocardial perfusion imaging.

BACKGROUND: Regadenoson (REGA), a selective adenosine A2A receptor agonist, is the most widely used stress agent for SPECT myocardial perfusion imaging (MPI) in the United States. The diagnostic accuracy of REGA MPI is comparable to Adenosine MPI, but its prognostic value is not well defined. METHODS: We categorized 1,400 patients (700 consecutive normal and 700 consecutive abnormal REGA-MPIs) into 4 groups based on the perfusion defect size using automated quantitative analysis: Group 1: normal perfusion; Group 2: <10% of left ventricle; Group 3: 10%-20%; Group 4: >20%. The primary outcome was a composite of cardiac death, myocardial infarction (MI), and late coronary revascularization (CR >90 days after MPI). RESULTS: Of the 1,400 patients (42% male, 37% diabetes, 21% heart failure, 26% end-stage renal disease), the primary outcome occurred in 23% (17% cardiac death, 4% MI, 6% late CR) during 46 ± 18 months of follow-up and 8% had early CR (within 90 days of MPI). Early CR occurred in 0.4%, 9%, 17%, and 17% and the primary outcome in 10%, 27%, 31%, and 43% in Groups 1-4, respectively (P < .001 for both). In an adjusted Cox proportional model, the hazard ratio for the primary outcome was 2.68 (1.77-4.06), 3.32 (2.28-4.83), and 4.05 (2.78-5.91) for Groups 2-4 compared to Group 1. CONCLUSION: REGA MPI provides powerful prognostic information that has important implications in patient management and can guide clinical practice.

Transesophageal echocardiographic diagnosis of bronchopulmonary vein fistula complicating mitral valve replacement.

A bronchopulmonary vein fistula (BVF) establishes a communication between a pulmonary vein and the alveolar space presumably secondary to alveolar rupture from increase in alveolar pressure. This rare fistula allows air to move continuously from the lungs to a pulmonary vein and into the left side of the heart causing systemic air embolization which is often fatal. We describe an adult patient undergoing a second mitral valve replacement surgery in whom intra-operative transesophageal echocardiography proved crucial in diagnosing BVF by showing persistent and increased streaming of air bubbles into the left heart from the left superior pulmonary vein during each positive pressure ventilation cycle with consequent inability to de-air the heart. This allowed initiation of appropriate management. The patient eventually had a fatal outcome from multiple organ infarcts.

The incremental value of three-dimensional transthoracic echocardiography in adult congenital heart disease.

Imaging with echocardiography is useful in diagnosing congenital heart disease (CHD). Two-dimensional (2D) transthoracic echocardiography (TTE) has been the standard cardiac imaging modality, but it forces the reader to mentally create the three-dimensional (3D) cardiac anatomy to understand these complex diseases. 3D TTE, which has relatively recently emerged to address this limitation, is capable of providing clear and dynamic 3D views of these anatomic defects and offers more insight on how to manage them. This review article will address the benefit of utilizing 3D TTE for proper characterization of different types of CHD in the adult and as a guide to appropriate treatment.