Table 2.

Longitudinal studies assessing the association of arterial stiffness with cardiovascular risk, renal outcomes, and mortality in renal transplant recipients.

Study ID	N	Population characteristics	Follow-up/Time points	Arterial stiffness assessment	Results
RETROSPECTIVE STUDIES
Kim et al. (52)	171	171 ESRD pts eligible for Tx, in 84 of whom follow-up baPWV was available	Before Tx and 1 year after Tx	baPWV VP-1000 BP203RPEII (Colin Company, Kyoto, Japan)	Pre-transplant baPWV was higher in patients with history of CVD than in those without (18 ± 4.4 vs. 14.91 ± 2.65 m/s, p < 0.05) and was a strong predictor of CVD (OR1.003, 95% CI: 1.001 to 1.005, p < 0.05). The optimal cut-off value of baPWV for the detection of CVD was 15.91 m/s and this value was an independent predictor of CVD in RTRs (OR 6.3, p < 0.05). Moreover, the occurrence rate of CVD was significantly higher in patients with “high coronary calcium score” compared to those with a “low coronary calcium score” and baPWV was also significantly higher to the first when comparing the two groups (16.27 ± 3.93 vs. 14.79 ± 2.65 m/s, p < 0.05)
Dahle et al. (53)	1,040	Renal transplant recipients	Follow-up 4.2 years	Aortic PWV Sphygmocor	Each 1 m/s increase in PWV up to 12 m/s, was significantly associated with mortality (HR 1.36, 95% CI 1.14 to 1.62, p = 0.001). An interquartile range increase of 3.8 m/s tripled the risk of mortality (HR 3.21, 95% CI 1.63 to 6.31), an effect similar to the effect of 1 interquartile increase in age (21.6 years, with an estimated HR of 3.06, 95% CI 1.87 to 5.29)
Cheddani et al. (54)	220	Renal transplant recipients	Time points 3 months and 1 year after Tx Follow-up 5.5 years	c-f PWV Complior	c-f PWV 3 months after transplantation was an independent risk factor for mortality (HR: 1.38, 95% CI 1.18 to 1.62, p < 0.001). Mortality was also significantly associated with c-f PWV 12 months after transplantation (HR 1.34, 95% CI 1.1 to 1.64, p = 0.004), but surprisingly not with aortic stiffness change between 3 and 12 months (HR 1.09, 95% CI 0.71 to 1.76, p = 0.696)
PROSPECTIVE STUDIES
Bahous et al. (55)	106	Renal transplant recipients	Follow-up 54.3 ± 28.9 months	aortic PWV Complior	Aortic PWV increased in RTRs independently of age and mean BP. Acute renal rejection (β 1.15, p = 0.01) and smoking (β 0.02, p = 0.025) were the principal factors modulating the increase of aortic PWV and the reduction of GFR. Occurrence of renal and/or cardiovascular events following transplantation was influenced by heart rate (HR, 7.16; p < 0.001) and PWV (HR. 0.25; p < 0.006)
Claes et al. (56)	253	Renal transplant recipients	Follow-up 3 years	c-f PWV SphygmoCor	When accounting for age, gender, and CV history, AC score (HR, 1.09 per 1 unit increase; 95% CI 1.02 to 1.17) and PWV (HR 1.45 per 1 m/s; 95% CI 1.16 to 1.8) remained an independent predictor of CV events in Cox-regression analyses. Using ROC the area under the curve for predicting CV events amounted to 0.80 and 0.72 for sum AC and PWV, respectively
Laucyte-Cibulskiene et al. (57)	37	Renal transplant recipients	Time points Before and year after Tx	c-f PWV, c-r PWV SphygmoCor	Pretransplant CRP level (HR 1.660, p = 0.007) and PWV ratio (cfPWV/crPWV) (HR 7.549, p = 0.045) predict cardiovascular events
Bahous et al. (58)	190	Renal transplant recipient-donor pairs	Follow-up 56 ± 18 months	Aortiv PWV Complior	Borderline significant association of donor aortic PWV with the composite outcome (occurrence of a fatal or nonfatal CV event and/or doubling of serum creatinine or development of ESRD) (RR 1.8, 95% CI 1 to 3.4, p = 0.05). When renal and CV outcomes were separately analyzed, recipient eGFR and donor PWV were significant determinants of the renal outcome (HR 0.26, 95% CI 0.14 to 0.4, p < 0.0001 and HR 1.9, 95% CI 1.2 to 3.0, p = 0.02, respectively) and previous history of CV events was the only significant determinant of the CV outcome (HR 3.5, 95% CI 2.1 to 8, p = 0.001).