Comparison between two strategies for rejection detection after heart transplantation: routine endomyocardial biopsy versus gallium-67 cardiac imaging

Systematic Review of Health Economic Evaluations of Diagnostic Tests in Brazil: How accurate are the results?

The aim of this study is to identify and characterize the health economic evaluations (HEEs) of diagnostic tests conducted in Brazil, in terms of their adherence to international guidelines for reporting economic studies and specific questions in test accuracy reports. We systematically searched multiple databases, selecting partial and full HEEs of diagnostic tests, published between 1980 and 2013. Two independent reviewers screened articles for relevance and extracted the data. We performed a qualitative narrative synthesis. Forty-three articles were reviewed. The most frequently studied diagnostic tests were laboratory tests (37.2%) and imaging tests (32.6%). Most were non-invasive tests (51.2%) and were performed in the adult population (48.8%). The intended purposes of the technologies evaluated were mostly diagnostic (69.8%), but diagnosis and treatment and screening, diagnosis, and treatment accounted for 25.6% and 4.7%, respectively. Of the reviewed studies, 12.5% described the methods used to estimate the quantities of resources, 33.3% reported the discount rate applied, and 29.2% listed the type of sensitivity analysis performed. Among the 12 cost-effectiveness analyses, only two studies (17%) referred to the application of formal methods to check the quality of the accuracy studies that provided support for the economic model. The existing Brazilian literature on the HEEs of diagnostic tests exhibited reasonably good performance. However, the following points still require improvement: 1) the methods used to estimate resource quantities and unit costs, 2) the discount rate, 3) descriptions of sensitivity analysis methods, 4) reporting of conflicts of interest, 5) evaluations of the quality of the accuracy studies considered in the cost-effectiveness models, and 6) the incorporation of accuracy measures into sensitivity analyses.

Immunohistochemical quantification of inflammatory cells in endomyocardial biopsy fragments after heart transplantation: a new potential method to improve the diagnosis of rejection after heart transplantation

Inconsistencies in cardiac rejection grading systems corroborate the concept that the evaluation of inflammatory intensity and myocyte damage seems to be subjective. We studied in 36 patients the potential role of the immunohistochemical (IHC) counting of inflammatory cells in endomyocardial biopsy (EMB) as an objective tool, testing the hypothesis of correlation between the International Society for Heart and Lung Transplantation 2004 rejection and IHC counting of inflammatory cells. We observed a progressive increment in CD68+ cells/mm(2) (P = .000) and CD3+ cells/mm(2) (P = .000) with higher rejection grade. A strong correlation between the grade of cellular rejection and both CD68+ cells/mm(2) and CD3+ cells/mm(2) was obtained (P = .000). One patient with CD3+ and CD68+ cells/mm(2) above the upper limit of the 95% confidence interval for cells/mm(2) found in rejection grade 1R evolved to rejection grade 2R without treatment. In patients with 2R that did not respond to treatment the values of CD68+ or CD3+ cells were higher than the overall median values for rejection grade 2R. For diagnosis of rejection needing treatment, the CD68+ and CD3+ cells/mm(2) areas under the receiver operating characteristic curves were 0.956 and 0.934, respectively. IHC counting of mononuclear inflammatory infiltrate in EMB seems to have additive potential role in evaluation of EMB for the diagnosis and prognosis of rejection episodes.

Routine surveillance endomyocardial biopsy continues to detect significant rejection late after heart transplantation

BACKGROUND

The need for continued surveillance endomyocardial biopsies beyond the first year after cardiac transplantation is controversial. We evaluated the incidence of rejections requiring treatment (International Society Heart and Lung Transplantation grade 3A or greater) in patients 5 years or more after heart transplantation.

METHODS

We conducted a retrospective chart review of all patients who underwent at least 1 endomyocardial biopsy at our center 5 years or more after heart transplantation.

RESULTS

A total of 461 biopsies were performed in 77 patients 5 or more years after heart transplantation. Nine episodes of grade 3A or greater rejection were identified in 8 of 77 patients (10%). During the first year, 7.6% of biopsies were grade 3A or greater. Grade 3A rejection occurred in approximately 3.5% to 4% of biopsies during years 2 to 7. The overall incidence of procedural related complications at our institution was < 0.5%.

CONCLUSION

Endomyocardial biopsies continue to detect clinically significant rejection beyond 5 years after cardiac transplantation. The overall incidence of procedural related complications requiring treatment was low and none was life threatening. The absence of early rejection does not predict freedom from late rejection. Therefore, we continue to recommend surveillance biopsies in cardiac transplant recipients late after transplantation.

Evaluation of the potential role of color-coded tissue Doppler echocardiography in the detection of allograft rejection in heart transplant recipients

BACKGROUND

Color-coded tissue Doppler (TD) echocardiography can noninvasively quantify alterations in left ventricular (LV) systolic and diastolic function. The objective of this study was to test the hypothesis that TD may play a role in the detection of LV dysfunction associated with allograft rejection in heart transplant recipients.

METHODS AND RESULTS

Seventy-eight consecutive transplant recipients underwent 89 TD studies of posterior wall myocardial velocity gradient and mitral annular velocity within 1 hour of endomyocardial biopsy. Color TD echocardiographic images were digitized for semiautomated computer analysis. Histologic analysis revealed no significant rejection in 75 biopsies and significant rejection in 14. TD posterior wall peak systolic and diastolic velocity gradients were reduced significantly with rejection: 3.9 +/- 2.0 s(-1) versus 2.6 +/- 0.9 s(-1) and 5.4 +/- 2. 4 s(-1) versus 3.5 +/- 1.6 s(-1), respectively (P <.05 vs the nonrejecting group). Peak systolic and diastolic mitral annular velocities by TD were also reduced with rejection: 63 +/- 14 mm/s versus 49 +/- 12.4 mm/s and 90 +/- 23 mm/s versus 60 +/- 21 mm/s, respectively (P <.001 vs the nonrejecting group). A TD peak-to-peak mitral annular velocity >135 mm/s had 93% sensitivity, 71% specificity, and 98% negative predictive value for detecting rejection. Although TD was unable to discriminate between rejection and other causes of low velocity values, high TD velocity values were supportive of excluding rejection.

CONCLUSIONS

These data suggest that color-coded TD may play a potential role as a screening test to exclude rejection in heart transplant recipients. Although this method has the potential to decrease the number of biopsies, further testing in a larger series of transplant recipients with rejection is warranted.

New method for detection of heart allograft rejection: validation of sensitivity and reliability in a rat heterotopic allograft model

BACKGROUND

Patients with inflammatory heart muscle diseases would benefit from a safe, convenient, rapidly performed diagnostic technique with real-time results not involving tissue removal. We have performed a detailed evaluation of detection of heart allograft rejection by autofluorescence in a heterotopic abdominal rat heart allograft model ex vivo.

METHODS AND RESULTS

Recipient rats with allograft (Lewis to Fisher 344; n=71) and isograft (Lewis to Lewis; n=33) hearts, treated with cyclosporine or untreated, were killed at days 2, 4, 7, 14, 21, 28, and 56 after transplant. Nontransplant controls with (n=24) or without (n=24) immunosuppressive therapy were also studied. When the rats were killed, autofluorescence spectra were acquired under blue-light excitation from midtransverse ventricular sections of native and transplanted hearts. Corresponding sections were then evaluated pathologically by a modified International Society for Heart and Lung Transplantation (ISHLT) grading schema. The spectral differences between rejecting and nonrejecting hearts were quantified by linear discriminant functions, producing scores that decreased progressively with increasing severity of tissue rejection. Mean+/-SD discriminant function scores were 2.9+/-1.6, 1.8+/-2.2, -0.1+/-2.8, -1.2+/-2.3, and -2.3+/-3.0 for isografts and allograft ISHLT grades 0, I, II, and III, respectively (Spearman rank-order correlation -0.6; P<0.001, test for trend). Cyclosporine had no detectable effect on the spectra.

CONCLUSIONS

The correlation between changes in autofluorescence spectra and ISHLT rejection grade strongly supports the possibility of catheter-based, fluorescence-guided surveillance of rejection.

Imaging of cardiac transplantation complications

Common complications of cardiac transplantation include infection, rejection, accelerated coronary artery atherosclerosis, and lymphoproliferative disease. The authors reviewed radiographic and computed tomographic (CT) features of cardiac transplantation and its complications in a series of 232 patients (with 89 complications and 49 deaths). Normal postoperative findings in the first few weeks after surgery included enlarged cardiac silhouette, pneumomediastinum, pneumothorax, pneumopericardium, subcutaneous emphysema, and mediastinal widening. Infection was the most common complication, with pneumonia being the leading infectious condition (28 cases, with Aspergillus [n = 11] and cytomegalovirus [n = 10] being the most common pathogens) and the cause of death in seven cases. Although many cases of pulmonary infections occur in the first 3-4 months after surgery, in this series several cases developed up to 3 years afterward. Radiographic signs of acute rejection were nonspecific in the eight patients affected who died, and endomyocardial biopsy was used to confirm the suspected diagnosis. Accelerated atherosclerosis occurred in 13 patients between 10 months and 6.5 years after transplantation and led to death in eight. Lymphoproliferative disorders, which range from benign lymphoid hyperplasia to malignant lymphoma and which are the third leading cause of death beyond the immediate perioperative period in heart transplant recipients, developed in four patients who later died. Other complications related to endomyocardial biopsy and cardiothoracic surgery (i.e., pneumothorax, hemothorax, pneumomediastinum, mediastinitis, aortic dissection, aortic pseudoaneurysm, and pulmonary embolism) occurred in 31 cases and were diagnosed with radiography and CT.