Blunted hemodynamic response to pharmacological stress is predictive of mortality in liver transplant candidates.

BACKGROUND

The optimal method for evaluating coronary artery disease in liver transplant candidates (LTCs) remains controversial. To date no studies have compared the hemodynamic and symptomatic response to vasodilator stress between LTCs and patients without chronic liver disease.

METHODS

We conducted a retrospective study of LTCs who underwent regadenoson nuclear stress testing with either 99mTc-tetrofosmin single-photon emission computed tomography (SPECT; N = 224) or 82Rubidium positron emission tomography (N = 36). These patients were compared to controls matched for age, sex, body mass index, cardiovascular comorbidities, and imaging modality who underwent clinically indicated regadenoson stress test.

RESULTS

LTCs were less likely to experience symptoms in response to regadenoson than controls (65% vs 86 %, P < .001). Additionally, the increase in heart rate was blunted in LTCs (ΔHR: 13 beats per minute [bpm], interquartile range [IQR]: 11-15 vs 29 bpm, IQR: 27-31, P < .001). During the median follow-up period of 2.0 ± 1.5 years, 78 deaths occurred in LTCs. In the multivariable analysis, ΔHR (hazard ratio [HZR]: .975, 95% confidence interval [CI]: .951-.999, P = .042) and changes in diastolic blood pressure (ΔDBP, HZR: 1.037, 95% CI: 1.003-1.071, P = .031) were significantly associated with mortality regardless of Model for End-stage Liver Disease (MELD) score, age, cardiovascular comorbidities, and stress test results. In addition, LTCs with both high MELD score (≥15) and low ΔHR (≤10 bpm) had worse overall survival than patients with a low MELD score (<15) and high ΔHR (>10 bpm, HZR: 5.54, 95% CI: 3.21-9.53, P < .001), low MELD score and low ΔHR (HZR: 6.62, 95% CI: 3.25-13.49, P < .001), and high MELD score and low ΔHR (HZR: 2.91, 95% CI: 1.50-5.64, P = .002).

CONCLUSIONS

In this retrospective cohort analysis, LTCs exhibited a reduced hemodynamic response detected as lower ΔHR as well as fewer symptoms in response to regadenoson during stress testing. Reduced hemodynamic response was significantly associated with mortality and provided incremental prognostic value in addition to MELD score. Further prospective studies are required to validate these findings.