Pulmonary hypertension is closely related to arterial stiffness in renal transplant patients

Incidence, Clinical Correlates, and Outcomes of Pulmonary Hypertension After Kidney Transplantation: Analysis of Linked US Registry and Medicare Billing Claims

BACKGROUND

The incidence, risks, and outcomes associated with pulmonary hypertension (P-HTN) in the kidney transplant (KTx) population are not well described.

METHODS

We linked US transplant registry data with Medicare claims (2006-2016) to investigate P-HTN diagnoses among Medicare-insured KTx recipients (N = 35 512) using billing claims. Cox regression was applied to identify independent correlates and outcomes of P-HTN (adjusted hazard ratio [aHR] 95%LCLaHR95%UCL) and to examine P-HTN diagnoses as time-dependent mortality predictors.

RESULTS

Overall, 8.2% of recipients had a diagnostic code for P-HTN within 2 y preceding transplant. By 3 y posttransplant, P-HTN was diagnosed in 10.310.6%11.0 of the study cohort. After adjustment, posttransplant P-HTN was more likely in KTx recipients who were older (age ≥60 versus 18-30 y a HR, 1.912.403.01) or female (aHR, 1.151.241.34), who had pretransplant P-HTN (aHR, 4.384.795.24), coronary artery disease (aHR, 1.051.151.27), valvular heart disease (aHR, 1.221.321.43), peripheral vascular disease (aHR, 1.051.181.33), chronic pulmonary disease (aHR, 1.201.311.43), obstructive sleep apnea (aHR, 1.151.281.43), longer dialysis duration, pretransplant hemodialysis (aHR, 1.171.371.59), or who underwent transplant in the more recent era (2012-2016 versus 2006-2011: aHR, 1.291.391.51). Posttransplant P-HTN was associated with >2.5-fold increased risk of mortality (aHR, 2.572.843.14) and all-cause graft failure (aHR, 2.422.642.88) within 3 y posttransplant. Outcome associations of newly diagnosed posttransplant P-HTN were similar.

CONCLUSIONS

Posttransplant P-HTN is diagnosed in 1 in 10 KTx recipients and is associated with an increased risk of death and graft failure. Future research is needed to refine diagnostic, classification, and management strategies to improve outcomes in KTx recipients who develop P-HTN.

Pulmonary Artery Systolic Pressure Measured Intraoperatively by Right Heart Catheterization Is a Predictor of Kidney Transplant Recipient Survival

BACKGROUND The effect of pulmonary artery systolic pressure (PASP) measured by Swan-Ganz right heart catheter (SG-RHC) on kidney transplant recipient survival has not been previously studied. The objective of this study was to assess the relationships between PASP measured via SG-RHC, done intraoperatively at the time of initiating anesthesia at the beginning of kidney transplant surgery, and patient survival. Multiple comorbidities, time on dialysis before the transplantation, and graft function were also analyzed in our study. MATERIAL AND METHODS This was a retrospective cohort study using data from all consecutive patients undergoing kidney transplant between January 1, 2005 and December 31, 2009 at Tampa General Hospital. Kidney transplant recipients were divided into 2 groups: Group 1 with PASP <35 mmHg and group 2 with PASP ≥35 mmHg. Patients and graft survival data, time on dialysis before transplant, and comorbidities were compared between the 2 groups. RESULTS Only 363 patients were found to have a documented PASP measurement at the time of anesthesia induction for the transplant surgery, and were included in the specific analysis of our study. Patients with PASP ≥35 mmHg showed a significant decrease in survival in comparison to patients having PASP values <35 mmHg (HR 1.88; 95% CI 1.012 to 3.47, P=0.04). There was a significant positive correlation between time on dialysis and PASP (rho 0.20; 95% CI 0.09 to 0.30, p<0.001), as well as a significant difference in median time on dialysis between PASP <35 vs. PASP ≥35 (22 vs. 29 months, p=0.004). There were no significant differences in graft failure between the 2 PASP groups (HR 0.34; 95% CI 0.12 to 1.01, P=0.05). CONCLUSIONS Patients with PASP ≥35 mmHg, measured intraoperatively by SG-RHC, showed significantly shorter survival in comparison to patients having PASP values <35 mmHg. This result suggests the need for a randomized controlled trial to address the importance of post-transplant pulmonary hypertension management in patient survival.

Pulmonary hypertension and post-operative outcome in renal transplant: A retrospective analysis of 170 patients

BACKGROUND AND AIMS

Renal transplant is the best possible treatment for patients suffering with end-stage renal disease (ESRD). Cardiovascular events are the commonest factors contributing to perioperative morbidity and mortality in this population. These patients have a high incidence (up to 60%) of pulmonary hypertension (PH) and that may affect the perioperative outcome.

METHODS

In this study, we aimed to study the impact of PH on perioperative outcome after renal transplant. PH was defined as patients with pulmonary artery systolic pressure ≥35 mmHg on pre-operative echocardiography. Medical records of 170 patients who had undergone renal transplantation in the past 3 years were reviewed. Primary outcome was delayed graft functioning and secondary outcomes were perioperative complications such as hypotension, arrhythmias, need of post-operative mechanical ventilation, atelectasis and pulmonary oedema.

RESULTS

We observed 46.5% incidence of PH in ESRD patients. Compared to patients without PH, more patients with PH had postoperative hypotension (26.58% vs. 9.89%, P = 0.004) and delayed graft functioning (8.8% vs. 1.1%, P = 0.026). On multivariate analysis, however, PH was not an independent predictor of delayed graft functioning.

CONCLUSION

In ESRD patients, although PH is not an independent predictor of delayed graft functioning, patients having PH are more prone for perioperative hypotension and delayed graft functioning after renal transplant.

The Intersection of Pulmonary Hypertension and Solid Organ Transplantation

Pulmonary hypertension (PH) is a complication and marker of disease severity in many parenchymal lung diseases. It also is a frequent complication of portal hypertension and negatively impacts survival with liver transplant. Pulmonary hypertension is frequently diagnosed in patients with end-stage renal disease who are undergoing dialysis, and it has recently been demonstrated to adversely affect posttransplant outcome in this patient population even though the mechanism of PH is substantially different from that associated with liver disease. The presence of PH in patients with heart failure is frequent, and the necessity for PH therapy prior to heart transplant has evolved in the last decade. We review the frequency of and risk factors for PH in recipients of and candidates for lung, liver, heart, and renal transplants as well as the impact of this diagnosis on posttransplant outcomes.