Prognostic value of peripheral arterial tonometry in patients with coronary artery disease and a high cardiovascular risk profile

Peripheral Artery Tonometry Reveals Impaired Endothelial Function before Percutaneous Coronary Intervention in Patients with Periprocedural Myocardial Injury

Background

Periprocedural myocardial injury (PMI) is a most common complication of percutaneous coronary intervention (PCI). Microembolization and inflammation underlying PMI could lead to coronary microvascular dysfunction (CMD) and vice versa. Reactive hyperemia index (RHI) assessed by peripheral artery tonometry (PAT) has been considered as a noninvasive method to assess endothelial function and CMD, which could be useful to predict PMI.

Methods

268 patients suspected with stable coronary artery disease (CAD) and scheduled for elective coronary angiography were enrolled. RHI was measured by using the Endo-PAT2000™ device before angiography. The association among RHI, PMI, and cardiovascular events was further assessed.

Results

In this cohort, 189 patients (70.5%) were diagnosed with CAD and 119 patients (44.4%) underwent drug-eluting stent (DES) implantation. Compared with patients without CAD, CAD patients had lower RHI (1.88 ± 0.55 vs. 2.02 ± 0.58, P < 0.05). Patients with PMI had a lower RHI before angiography (1.75 ± 0.37 vs. 1.95 ± 0.50, P < 0.05). Receiver operating characteristic curve analysis of RHI revealed an area under the curve (AUC) of 0.61, with a sensitivity of 62.7% and specificity of 50.0% to predict PMI. Moreover, we found that CAD patients with RHI ≤ 1.81 had a higher incidence of composite cardiac events after stenting (adjusted hazard ratio (HR) 3.31, 95% confidence interval (CI) 1.07–10.22, P < 0.05).

Conclusions

RHI assessment through PAT could be a promising method to predict PMI before the procedure. RHI is associated with increased risk of long-term adverse cardiac events after DES implantation.

Endothelial function as predictor in patients with coronary syndrome treated by percutaneous coronary intervention

We aimed at identifying the predictive role of endothelial function assessed by the RH-PAT index (RHI) for future major cardiovascular events (MACEs) in acute coronary syndrome (ACS) patients treated with percutaneous coronary intervention (PCI). We measured RHI in 308 subjects with ACS, and they were divided into the normal endothelial function (NEF) group and the endothelial dysfunction (DEF) group according to the RHI. The subjects were followed up for a mean of 16 months (interquartile range [IQR]: 14–20 months) after PCI treatment, and their MACEs were also recorded. Cumulative incidence curves were constructed for time-to-event variables with Kaplan–Meier estimates and compared using the log-rank test. The overall incidence of MACEs was 25.39% in the DEF group and 15.96% in the NEF group (P<0.05). Kaplan–Meier analysis also demonstrated a significantly higher probability of MACEs in the DEF group than in the NEF group (log-rank test: P<0.05). Multivariate Cox hazard analysis identified RHI (Model 2, adjusted by blood pressure, hazard ratio [HR]: 0.425; 95% confidence interval [CI]: 0.198–0.914; P=0.029) and SYNTAX score (HR: 1.043; 95% CI: 1.019–1.067; P<0.001) as independent predictors of future MACEs after PCI treatment in ACS patients. Endothelial function measured by reactive hyperemia-peripheral arterial tonometry (RH-PAT) is impaired in ACS subjects treated with PCI. The RHI was an independent predictor of MACEs, suggesting that RHI may be useful as a candidate biomarker in the risk stratification of patients with ACS after PCI treatment.

Endothelial dysfunction and the occurrence of radial artery spasm during transradial coronary procedures: the ACRA-Spasm study

AIMS

The aim of this study was to analyse the relation between endothelial dysfunction (ED) and the occurrence of radial artery spasm (RAS) during transradial coronary procedures.

METHODS AND RESULTS

From May 2014 to June 2015, endothelial function was assessed by EndoPAT and FMD before the procedure in 165 patients referred for coronary angiography or intervention. The primary endpoint was RAS, defined by patient's symptoms and procedural characteristics. The mean age of the study population was 63 years and 71% were male. In total 16% of the patients experienced RAS. The incidence of RAS did not differ between patients with and without ED (13.8% vs. 20.2%, OR 0.63, 95% CI: 0.25-1.58, p=0.32). The strongest predictors of RAS were a ratio of radial artery inner diameter and sheath outer diameter smaller than 1 (OR 4.7, 95% CI: 1.35-16.5, p=0.009) and a combination of clinical characteristics presented as an RAS risk score of at least 4 (p=0.007, OR 3.7, 95% CI: 1.37-9.89).

CONCLUSIONS

Endothelial dysfunction was not found to be a predictor of the occurrence of radial artery spasm in a cohort of patients undergoing elective heart catheterisation. Radial artery-sheath mismatch is the strongest pre-procedural predictor of RAS.

The Relationship between Endothelial Dysfunction and Endothelial Cell Markers in Peripheral Arterial Disease

INTRODUCTION

The endothelial function plays key roles in both promoting and protecting against atherosclerotic disease. Several methods, including peripheral arterial tonometry (PAT), have been reported to be useful for investigating endothelial dysfunction. Furthermore, the level of thrombomodulin (TM) is assumed to reflect the endothelial dysfunction. In the present study, we investigated endothelial dysfunction in patients with peripheral arterial disease (PAD) by measuring their TM levels, and evaluated the correlation between TM and various parameters.

MATERIALS AND METHODS

We measured the TM levels and performed PAT in 17 patients with PAD. We also recorded the patients' demographic information, including comorbidities, and investigated their hemodynamic status by measuring the ankle brachial pressure index (ABI). The PAT results were used to calculate the reactive hyperemia index (RHI), which reflected the patients' level of endothelial dysfunction.

RESULTS

The RHI and ABI values and the serum level of creatinine were found to be significantly correlated with the TM level (P = 0.040, 0.041 and 0.005, respectively). After setting an RHI value of 1.67 as the cut-off, the patients with RHI values of <1.67 were found to have significantly higher TM levels (median, 20.3 U/mL) than the patients with RHI values of ≥1.67 (median, 13.7 U/mL) (P = 0.023).

CONCLUSIONS

The degree of endothelial dysfunction, as calculated by the TM level, might influence the prognostic value of the RHI, which is determined by PAT. The measurement of the TM level and PAT might both be useful methods of measuring endothelial dysfunction in patients with PAD.

Reducing Microvascular Dysfunction in Revascularized Patients with ST-Elevation Myocardial Infarction by Off-Target Properties of Ticagrelor versus Prasugrel. Rationale and Design of the REDUCE-MVI Study

Microvascular injury is present in a large proportion of patients with ST-elevation myocardial infarction (STEMI) despite successful revascularization. Ticagrelor potentially mitigates this process by exerting additional adenosine-mediated effects. This study aims to determine whether ticagrelor is associated with a better microvascular function compared to prasugrel as maintenance therapy after STEMI. A total of 110 patients presenting with STEMI and additional intermediate stenosis in another coronary artery will be studied after successful percutaneous coronary intervention (PCI) of the infarct-related artery. Patients will be randomized to treatment with ticagrelor or prasugrel for 1 year. FFR-guided PCI of the non-infarct-related artery will be performed at 1 month. Microvascular function will be assessed by measurement of the index of microcirculatory resistance (IMR) in the infarct-related artery and non-infarct-related artery, immediately after primary PCI and after 1 month. The REDUCE-MVI study will establish whether ticagrelor as a maintenance therapy may improve microvascular function in patients after revascularized STEMI.

Time Rate of Blood Pressure Variation Is Associated With Endothelial Function in Patients With Metabolic Syndrome

The time rate of blood pressure (BP) variation indicates the speed of BP fluctuations. Previous studies have demonstrated that the time rate of BP variation was associated with target organ damage. However, the association between time rate of BP variation and endothelial function has not been evaluated.24-hour ambulatory blood pressure monitoring (ABPM) was performed in 61 patients with metabolic syndrome. Time rate of BP variation was calculated from BP recordings of ABPM. Endothelial function was assessed using reactive hyperemia-peripheral arterial tonometry index (RHI) by EndoPat2000. Multiple linear regression models were used to detect the association between time rate of BP variation and RHI.Among all the subjects (n = 61), the multiple linear regression models revealed that the daytime rate of systolic blood pressure (SBP) variation was independently associated with RHI (β = -0.334, P = 0.008). A 0.1 mmHg/minute increase in the daytime rate of SBP variation correlated with a decline of 0.20 in RHI. The same effect was also found in the subjects with eGFR ≥ 60 mL/ (minute*1.73 m(2)). A greater association was found in those who were not taking a statin, β-blocker, ACEI/ARB, or diuretic and those without diabetes compared with those with any antihypertensive medication or with diabetes. Other ambulatory blood pressure parameters and central hemodynamics were not found to be associated with RHI.Our findings have shown that the daytime rate of SBP variation was associated with endothelial function in patients with metabolic syndrome, independent of other BP parameters and central hemodynamics.

Effect of Ivabradine on Endothelial Function in Patients with Stable Angina Pectoris: Assessment with the Endo-PAT 2000 Device

INTRODUCTION

Ivabradine has opened up new possibilities for treating stable angina and chronic heart failure by lowering heart rate. Ivabradine lowers heart rate by selectively inhibiting the I f current in the sinoatrial node. This study aimed to determine whether the decrease in heart rate achieved with ivabradine was accompanied by hemodynamic changes that might lead to an enhancement of endothelial function.

METHODS

Thirty patients with stable angina pectoris were included in the study. Ivabradine (5 mg bid) was added to the recommended standard treatment. Endothelial function was assessed at baseline and after 3 months of ivabradine therapy, with an Endo-PAT 2000 device (Itamar Medical, Israel). This device was recently developed for the noninvasive assessment for endothelial dysfunction. We evaluated reactive hyperemia index (RHI), which reflects endothelial function, and augmentation index (AI), which provides an indication of arterial stiffness.

RESULTS

The study population consisted of 25 (83.3%) men and five (16.7%) women. The mean age of the patients was 65.4 ± 6.7 years. Twenty-eight (93.3%) patients had a history of myocardial infarction (ST-segment elevation myocardial infarction or non-ST-segment elevation myocardial infarction), 23 (76.6%) had undergone revascularization (percutaneous coronary intervention or coronary artery bypass graft), 16 (53.3%) had type 2 diabetes mellitus, and 29 (96.6%) had arterial hypertension. The mean resting heart rate decreased significantly, from 77 ± 7 bpm at the start of the study to 65 ± 6 bpm after treatment (P < 0.0001). Endothelial function was found to have improved significantly after 3 months of ivabradine therapy. Mean RHI before treatment was 1.54 ± 0.30, suggesting probable endothelial dysfunction, whereas mean RHI at the end of the study was 1.83 ± 0.36 (P < 0.0001). AI also improved significantly on treatment, from 21 ± 20% to 10 ± 21% (P < 0.0001).

CONCLUSION

The addition of ivabradine to the treatment regimen of patients with stable angina pectoris both lowered heart rate and improved endothelial function. However, broader, randomized, double-blind, placebo-controlled clinical trials are required to confirm these findings.