The utility of myocardial perfusion imaging before renal transplantation: a retrospective analysis

Renal transplantation (RT) reduces morbidity and mortality in patients with end-stage renal failure. Myocardial perfusion imaging provides prognostic information in patients with renal failure, but its role before transplantation remains unclear. We performed a retrospective review assessing the prognostic value of technetium-99m sestamibi myocardial perfusion imaging at a tertiary UK centre.

We included scans performed between 2005 and 2012. Available scans were reanalysed to calculate the semiquantitative summed scores: sum rest score (SRS), sum stress score (SSS), sum difference score and sum motion score (SMS). Kaplan-Meier survival estimates assessed all-cause mortality and cardiac events according to scan findings, transplant decision and SSS. Cox-proportional hazards tested for an association between clinical/scan variables and all-cause mortality, and combined all-cause mortality/cardiovascular (CV) events.

One hundred and thirty-eight scans were identified with complete follow-up. During a median 40.4-month follow-up, 21 patients died, with 11 nonfatal CV events. There was no significant difference between groups according to scan findings for mortality (log-rank P=0.17) or mortality/CV events (P=0.06). An SSS greater than 8 was associated with higher mortality and CV events combined (P=0.028). An abnormal baseline ECG [hazard ratio (HR): 16.1] and higher SRS (HR: 2.3) were associated independently with higher mortality; an abnormal ECG (HR: 3.4) also predicted higher cardiac events/mortality.

Moderate to severe perfusion defects by SSS were associated with higher mortality and CV events. Higher SRS was associated independently with increased mortality on multivariable analysis, highlighting a key role for semiquantitative analysis methods for risk stratification. An abnormal ECG was associated strongly with both endpoints, and may be a useful screening tool to select patients for further investigation.