Surface electrocardiography and histologic rejection following orthotopic heart transplantation

The role of the electrocardiogram in the recognition of cardiac transplant rejection: A systematic review and meta‐analysis

Background

In cardiac transplant recipients, the electrocardiogram (ECG) is a noninvasive measure of early allograft rejection. The ECG can predict an acute cellular rejection, thus shortening the time to recognition of rejection. Earlier diagnosis has the potential to reduce the number and severity of rejection episodes.

Methodology

A systematic literature review was conducted to identify and select the original research reports on using electrocardiography in diagnosing cardiac transplant rejection in accordance with the PRISMA guidelines. Studies included reported sensitivity and specificity of ECG readings in heart transplant recipients during the first post‐transplant year. Data were analyzed with Review manager version 5.4. p‐value was used in testing the significant difference.

Results

After the removal of duplicates, 98 articles were eligible for screening. After the full‐text screening, a total of 17 papers were included in the review based on the above criteria. A meta‐analysis of five studies was done.

Conclusion

In heart transplant recipients, a noninvasive measure of early allograft rejection has the potential to reduce the number and severity of rejection episodes by reducing the time and cost of surveillance of rejection and shortening the time to recognition of rejection.

Non-invasive cardiac allograft rejection surveillance: reliability and clinical value for prevention of heart failure

Allograft rejection-related acute and chronic heart failure (HF) is a major cause of death in heart transplant recipients. Given the deleterious impact of late recognized acute rejection (AR) or non-recognized asymptomatic antibody-mediated rejection on short- and long-term allograft function improvement of AR surveillance and optimization of action strategies for confirmed AR can prevent AR-related allograft failure and delay the development of cardiac allograft vasculopathy, which is the major cause for HF after the first posttransplant year. Routine non-invasive monitoring of cardiac function can improve both detection and functional severity grading of AR. It can also be helpful in guiding the anti-AR therapy and timing of routine surveillance endomyocardial biopsies (EMBs). The combined use of EMBs with non-invasive technologies and methods, which allow detection of subclinical alterations in myocardial function (e.g., tissue Doppler imaging and speckle-tracking echocardiography), reveal alloimmune activation (e.g., screening of complement-activating donor-specific antibodies and circulating donor-derived cell-free DNA) and help in predicting the imminent risk of immune-mediated injury (e.g., gene expression profiling, screening of non-HLA antibodies, and circulating donor-derived cell-free DNA), can ensure the best possible surveillance and management of AR. This article gives an overview of the current knowledge about the reliability and clinical value of non-invasive cardiac allograft AR surveillance. Particular attention is focused on the potential usefulness of non-invasive tools and techniques for detection and functional grading of early and late ARs in asymptomatic patients. Overall, the review aimed to provide a theoretical and practical basis for those engaged in this particularly demanding up-to-date topic.

Statin-associated QTc Interval Shortening as Prognostic Indicator in Heart Transplant Recipients

Statin treatment promotes survival after cardiac transplantation by reducing cholesterol levels, allograft rejection, and transplant coronary artery disease. Analysis of data from 114 heart transplant recipients (including 86 treated with statins for < or =1 year post-transplantation) revealed that statins were associated with shortened corrected QT intervals (QTc), reduced low-density lipoprotein cholesterol, and reduced transplant coronary artery disease incidence at 1 year and improved survival at 5 years. Statin-associated QTc shortening thus appears to be a favorable prognostic sign after transplantation.

Relation of QTc duration heterogeneity to mortality following orthotopic heart transplantation

Studies of heart failure patients have demonstrated that serial QT prolongation and abnormally prolonged QT intervals are associated with greater mortality. Serial QT interval measurements in patients who undergo orthotopic heart transplantation (OHT) may quantify the degree of myocardial repolarization heterogeneity and serve as a marker of arrhythmogenic substrate. In this study, the mean survival for those with "stable" QT(c) intervals (a change of -10 to 10 ms/year) was 124 +/- 8 months versus 63 +/- 25 months in those with annual QT(c) changes of >10 ms (p = 0.009). Ventricular repolarization heterogeneity may serve as a marker of identifying high-risk patients after OHT.