Evaluation after Orthotopic Heart Transplant: What the Radiologist Should Know.

Orthotopic heart transplant (OHT) is the treatment of choice for end-stage heart disease. As OHT use continues and postoperative survival increases, multimodality imaging evaluation of the transplanted heart will continue to increase. Although some of the imaging is performed and interpreted by cardiologists, a substantial proportion of images are read by radiologists. Because there is little to no consensus on a systematic approach to patients after OHT, radiologists must become familiar with common normal and abnormal posttreatment imaging features. Intrinsic transplant-related complications may be categorized on the basis of time elapsed since transplant into early (0-30 days), intermediate (1-12 months), and late (>12 months) stages. Although there can be some overlap between stages, it remains helpful to consider the time elapsed since surgery, because some complications are more common at certain stages. Recognition of differing OHT surgical techniques and their respective postoperative imaging features helps to avoid image misinterpretation. Expected early postoperative findings include small pneumothoraces, pleural effusions, pneumomediastinum, pneumopericardium, postoperative atelectasis, and an enlarged cardiac silhouette. Early postoperative complications also can include sternal dehiscence and various postoperative infections. The radiologist's role in the evaluation of allograft failure and rejection, endomyocardial biopsy complications, cardiac allograft vasculopathy, and posttransplant malignancy is highlighted. Because clinical manifestations of disease may be delayed in transplant recipients, radiologists often recognize postoperative complications on the basis of imaging and may be the first to suggest a specific diagnosis and thus positively affect patient outcomes. Online supplemental material is available for this article. ©RSNA, 2019.

Rethinking composite end points in clinical trials: insights from patients and trialists.

BACKGROUND: Many clinical trials use composite end points to reduce sample size, but the relative importance of each individual end point within the composite may differ between patients and researchers. METHODS AND RESULTS: We asked 785 cardiovascular patients and 164 clinical trial authors to assign 25 "spending weights" across 5 common adverse events comprising composite end points in cardiovascular trials: death, myocardial infarction, stroke, coronary revascularization, and hospitalization for angina. We then calculated end point ratios for each participant's ratings of each nonfatal end point relative to death. Whereas patients assigned an average weight of 5 to death, equal or greater weight was assigned to myocardial infarction (mean ratio, 1.12) and stroke (ratio, 1.08). In contrast, clinical trialists were much more concerned about death (average weight, 8) than myocardial infarction (ratio, 0.63) or stroke (ratio, 0.53). Both patients and trialists considered revascularization (ratio, 0.48 and 0.20, respectively) and hospitalization (ratio, 0.28 and 0.13, respectively) as substantially less severe than death. Differences between patient and trialist end point weights persisted after adjustment for demographic and clinical characteristics (P<0.001 for all comparisons). CONCLUSIONS: Patients and clinical trialists did not weigh individual components of a composite end point equally. Whereas trialists are most concerned about avoiding death, patients place equal or greater importance on reducing myocardial infarction or stroke. Both groups considered revascularization and hospitalization as substantially less severe. These findings suggest that equal weights in a composite clinical end point do not accurately reflect the preferences of either patients or trialists.

Incremental utility of iodine-123 meta-iodobenzylguanidine imaging beyond established heart failure risk models.

BACKGROUND: Nuclear myocardial imaging with iodine-123 meta-iodobenzylguanidine ((123)I-mIBG) is approved for risk stratification of patients with systolic heart failure (HF). Whether (123)I-mIBG imaging provides incremental prognostic utility beyond established risk models remains unclear. METHODS AND RESULTS: In a multicenter study, 961 patients with moderate systolic HF underwent (123)I-mIBG imaging and were followed for cardiac death, progressive HF, or life-threatening arrhythmias over 2 years. We constructed 4 multivariable models, using variables from each of 4 published HF risk models, and patient-level scores were calculated both before and after adding the heart-to-mediastinum ratio (H/M) from (123)I-mIBG imaging. Incremental utility was evaluated by calculating integrated discrimination improvement (IDI), which quantifies the increase in probability of experiencing the primary end point after adding H/M to each model. The composite end point occurred in 25% of patients. After adding H/M, absolute IDI ranged from 2.1% to 3.0%, representing 33%-59% relative improvements in risk stratification. Of note, hazard ratios for H/M were remarkably similar between risk models (0.40-0.44 for predicting the composite end point, 0.10-0.18 for mortality; all P < .001). CONCLUSIONS: Despite notable differences in predictor variables, patient populations, and analytic techniques from which each model was initially derived, adding (123)I-mIBG data to HF risk models consistently identified patients at lower risk of experiencing adverse events.

Aberrant right subclavian artery-esophageal fistula and severe gastrointestinal bleeding after surgical correction of scimitar syndrome.

Scimitar syndrome and gastrointestinal bleeding from an aberrant right subclavian artery-esophageal fistula are each extremely rare. Although scimitar syndrome and aberrant right subclavian artery are typically asymptomatic in adults, fistulous connection between the aberrant artery and the esophagus is associated with a poor prognosis. Outcomes are contingent upon timely diagnosis and prompt surgical repair. Prolonged nasogastric and endotracheal intubation can lead to gastrointestinal bleeding in patients who have an aberrant right subclavian artery or other vascular ring. We recommend neither embolization nor the use of endovascular stents as anything other than a temporizing measure in the management of aberrant right subclavian artery injury. These methods can stop acute hemorrhage; however, sentinel bleeding will eventually occur and require definitive ligation. We report the case of a 57-year-old woman in whom an aberrant right subclavian artery-esophageal fistula developed after surgical correction of symptomatic scimitar syndrome. Massive gastrointestinal bleeding resulted from prolonged nasogastric and endotracheal intubation. To our knowledge, this is the first report of aberrant right subclavian artery and scimitar syndrome in the same patient, and the 4th report of a patient's surviving a fistula between the aberrant artery and the esophagus.