Right Ventricular Function on Cardiovascular Magnetic Resonance Imaging and Long-Term Outcomes in Stable Heart Transplant Recipients

BACKGROUND

In heart transplant recipients, right ventricular (RV) dysfunction may occur for a variety of reasons. Whether RV dysfunction in the stable phase after heart transplantation is associated with long-term adverse outcomes is unknown. We aimed to determine the long-term prognostic significance of RV dysfunction identified on cardiovascular magnetic resonance imaging (CMR) at least 1 year after heart transplantation.

METHODS

In consecutive heart transplant recipients who underwent CMR for surveillance, we assessed 2 CMR measures of RV function: RV ejection fraction and RV global longitudinal strain (RVGLS). We investigated associations between RV dysfunction and a composite end point of death or major adverse cardiac events, including retransplantation, nonfatal myocardial infarction, coronary revascularization, and heart failure hospitalization.

RESULTS

A total of 257 heart transplant recipients (median age, 59 years; 75% men) who had CMR at a median of 4.3 years after heart transplantation were included. Over a median follow-up of 4.4 years after the CMR, 108 recipients experienced death or major adverse cardiac events. In a multivariable Cox regression analysis adjusted for age, time since transplantation, indication for transplantation, cardiac allograft vasculopathy, history of rejection, and CMR covariates, RV ejection fraction was not associated with the composite end point, but RVGLS was independently associated with the composite end point with a hazard ratio of 1.08 per 1% worsening in RVGLS ([95% CI, 1.00-1.17]; P=0.046). RVGLS provided incremental prognostic value over other variables in multivariable analyses. The association was replicated in subgroups of recipients with normal RV ejection fraction and recipients with late gadolinium enhancement imaging. A similar association was seen with a composite end point of cardiovascular death or major adverse cardiac events.

CONCLUSIONS

CMR feature tracking-derived RVGLS assessed at least 1 year after heart transplantation was independently associated with the long-term risk of death or major adverse cardiac events. Future studies should investigate its role in guiding clinical decision-making in heart transplant recipients.

Perioperative Management of Heart Transplantation: A Clinical Review

In this clinical review, the authors summarize the perioperative management of heart transplant patients with a focus on hemodynamics, immunosuppressive strategies, hemostasis and hemorrage, and the prevention and treatment of infectious complications.

Thirty-year trends and outcome of isolated versus combined group 2 pulmonary hypertension after cardiac transplantation

Aim

To investigate the effect of the new definition of pulmonary hypertension (PH) and new pulmonary vascular resistance (PVR) thresholds on the prevalence, clinical characteristics, and events following cardiac transplantation (CTx) over 30 years.

Methods

Patients who underwent CTx between 1983 and 2014 for whom invasive hemodynamic data was available were analyzed (n = 342). Patients transplanted between 1983 and 1998 were classified as early era and those transplanted between 1999 and 2014 were classified as recent era. Group 2 PH was diagnosed in the presence of a mean pulmonary artery pressure (mPAP) > 20 mmHg and pulmonary capillary wedge pressure (PCWP) > 15 mmHg. Isolated post capillary PH (Ipc-PH) was defined as PVR ≤ 2 wood units and combined pre and post capillary PH (Cpc-PH) was defined PVR > 2 wood units. Moderate to severe PH was defined as mPAP ≥ 35 mmHg. The primary outcome was 30-day mortality and long-term mortality according to type and severity of PH. Proportions were analyzed using the chi-square test, and survival analyses were performed using Kaplan-Meier curves and compared using the logrank test.

Results

The prevalence of PH in patients transplanted in the early era was 89.1%, whilst 84.2% of patients transplanted in the recent era had PH (p = 0.3914). There was no difference in the prevalence of a pre-capillary component according to era (p = 0.4001), but severe PH was more common in the early era (51.1% [early] vs 38.0% [recent] p = 0.0151). Thirty-day and long-term  mortality  were  not  significantly  associated  with severity or type of PH. There was a trend toward increased 30-day mortality in mild PH (10.1%), compared to no PH (4.4%) and moderate to severe PH (6.6%; p = 0.0653). Long-term mortality did not differ according to the severity of PH (p = 0.1480). There were no significant differences in 30-day or long-term mortality in IpcPH compared to CpcPH (p = 0.3974 vs p = 0.5767, respectively).

Conclusion

Over 30 years, PH has remained very prevalent before CTx. The presence, severity, and type (pre- vs post-capillary) of PH is not significantly associated with short- or long-term mortality.

Lund exhaust on hemodynamic parameters and inflammatory mediators in patients undergoing cardiac valve replacement under cardiopulmonary bypass

The effect of Lund exhaust technique on hemodynamics and inflammatory mediators in patients undergoing cardiac valve replacement under cardiopulmonary bypass was evaluated. A total of 60 patients with heart disease undergoing elective heart valve replacement under elective cardiopulmonary bypass were randomly divided into Lund exhaust group (group A) and control group (group B), with 30 patients in each group. Group A underwent Lund exhaust during cardiopulmonary bypass, while group B was identical to group A except for not using the Lund exhaust technique during cardiopulmonary bypass. The hemodynamic parameters at different time-points showed that the indexes of MAP, PASP, CO, CI, PCWP, CVP and SVR in T₁, T₂, T₃ and T₄ moments between group A and group B were statistically significant (p<0.05). There was no statistical significance in IL-6, IL-8, IL-10, TNF-α and TIMP-1 between group A and group B patients at the T₀ moment (p>0.05). The levels of IL-6, IL-8, IL-10, TNF-α and TIMP-1 in group B patients at T₁, T₂, T₃ and T₄ moments were statistically significant compared with those in group A (p<0.05). The IL-6, IL-8, TNF-α indexes of group B patients were statistically significant at the T₅ moment compared with those in group A (p<0.05). The IL-10 and TIMP-1 of two groups were not statistically significant at the T₅ moment. The operating time, CPB time, aortic clamp time, intraoperative blood loss, postoperative tube time, ICU stay time, hospital stay time and pulmonary infection of patients in group A were significantly less than those in group B. In conclusion, Lund exhaust technology can significantly reduce the fluctuation of hemodynamics, decrease the expression of inflammatory factors, improve lung function, and is conducive to the rehabilitation of patients.

Biomarkers to Assess Right Heart Pressures in Recipients of a Heart Transplant: A Proof-of-Concept Study

Background

This proof-of-concept study investigated the feasibility of using biomarkers to monitor right heart pressures (RHP) in heart transplanted (HTx) patients.

Methods

In 298 patients, we measured 7.6 years post-HTx mean pressures in the right atrium (mRAP) and pulmonary artery (mPAP) and capillaries (mPCWP) along with plasma high-sensitivity troponin T (hsTnT), a marker of cardiomyocyte injury, and the multidimensional urinary classifiers HF1 and HF2, mainly consisting of dysregulated collagen fragments.

Results

In multivariable models, mRAP and mPAP increased with hsTnT (per 1-SD, +0.91 and +1.26 mm Hg; P < 0.0001) and with HF2 (+0.42 and +0.62 mm Hg; P ≤ 0.035), but not with HF1. mPCWP increased with hsTnT (+1.16 mm Hg; P < 0.0001), but not with HF1 or HF2. The adjusted odds ratios for having elevated RHP (mRAP, mPAP or mPCWP ≥10, ≥24, ≥17 mm Hg, respectively) were 1.99 for hsTnT and 1.56 for HF2 (P ≤ 0.005). In detecting elevated RHPs, areas under the curve were similar for hsTnT and HF2 (0.63 vs 0.65; P = 0.66). Adding hsTnT continuous or per threshold or HF2 continuous to a basic model including all covariables did not increase diagnostic accuracy (P ≥ 0.11), whereas adding HF2 per optimized threshold increased both the integrated discrimination (+1.92%; P = 0.023) and net reclassification (+30.3%; P = 0.010) improvement.

Conclusions

Correlating RHPs with noninvasive biomarkers in HTx patients is feasible. However, further refinement and validation of such biomarkers is required before their clinical application can be considered.