Shrunken pore syndrome in heart transplantation: a pore ready to close?

Background: A newly discovered renal syndrome, shrunken pore syndrome (SPS), has been shown to increase mortality regardless of renal function. SPS is defined as an estimated glomerular filtration rate (eGFR) of cystatin C ≤ 60% than eGFR_creatinine. We set out to study SPS in relation to the survival of heart transplantation patients with a follow-up of up to 12 years. Methods. This was a single-center cohort study including 253 consecutive patients undergoing heart transplantation. The prevalence of SPS at different time points post-transplantation and its effect on survival was evaluated using Kaplan-Meier's analysis and multivariable Cox proportional hazards regression. Results. The prevalence of SPS was 7.5% the day after transplantation (D1), which rose to 71% week 4 after surgery. There was no difference in survival for patients with SPS D1 compared to patients without SPS D1. Patients with SPS 4 weeks compared to patients without SPS 4 weeks after transplantation showed a 5- and 10-year survival of 73% vs. 93% (p = .02) and 63% vs. 90% (p = .005), respectively. SPS developed during the postoperative period was also found to be an independent predictor of mortality (HR 4.65; 95% CI 1.36-15.8). Discussion. SPS that developed in the postoperative course after heart transplantation was found to be an independent predictor of mortality with a severe negative impact on 5- and 10-year survival.