Abnormal vascular function in PR-interval prolongation

Can prolonged P-R interval predict clinical outcomes in non-ST elevation acute coronary syndrome patients?

BACKGROUND

The present study aimed to respond to clinical question, can prolonged P-R interval predict clinical outcomes in non-ST elevation acute coronary syndrome patients?

METHODS

This descriptive-analytical study was conducted on cardiac patients. All of the non-ST elevation acute coronary syndrome (NSTEACS) including non-ST elevation myocardial infarction (NSTEMI) and unstable angina patients included in the study. Then they divided into two groups: prolonged P-R interval and normal P-R interval. The patients who had a history of digoxin and calcium channel blocker use, using antiarrhythmic drugs, known valvular or congenital heart disease and connective tissue, unreadable P-R interval and cardiac block were excluded. Data were collected using the questionnaire consisted demographic data and clinical outcomes and a follow-up part was completed by one of the researchers.

RESULTS

Finally, 248 patients completed the study. The results showed both of the two groups had significant differences in terms of the history of myocardial infarction (MI) (p = 0.018), the level of high-density lipoprotein (HDL) (p = 0.004), heart rate (p = 0.042), inverted T wave (p = 0.017), anterior ST- segment depression (p = 0.008), normal report of coronary angiography (CAG) (p = 0.003), three vessels disease (p = 0.043), left main lesion (p = 0.045) and SYNTAX score (p = 0.032) based on the CAG report. The results of six-month follow-up showed although, the frequency of ischemic stroke, coronary artery disease (CAD) and cardiovascular death were higher in prolonged P-R interval groups. The chi-square test showed this difference was statistically non-significant (p > 0.05). The multivariate logistic regression model revealed non-significant relationships between prolonged P-R interval and SYNTAX score, significant CAD, three-vessel disease, inverted T wave, anterior ST depression, heart rate and HDL.

CONCLUSIONS

Based on the results of our study the six-month follow-up showed non-significant outcomes. Further studies are recommended to assess the long-term outcomes.

Epidemiology and Outcomes Associated with PR Prolongation

PR prolongation is defined primarily as delayed conduction through the AV node, but can also signify delayed electrical impulse propagation through any part of the conduction system. The prevalence of PR prolongation ranges from 1% to 5% in patients younger than 50 years, with increasing prevalence, after the sixth decade of life and in patients with organic heart disease. Contemporary studies have documented increased risk of atrial arrhythmias, heart failure, and mortality in patients with PR prolongation. Future studies are needed to more accurately risk stratify elderly patients with PR prolongation who may be at increased risk of adverse outcomes.

Cardio-ankle brachial index is associated with prolonged Tp-e interval in patients with arterial hypertension

AIM

The cardio-ankle vascular index (CAVI) is a marker of arterial stiffness, and elevated CAVI values have been reported to be associated with an increased risk of cardiovascular mortality and cardiac arrhythmia. This study aimed to evaluate the relationship between Tp-e interval and CAVI, which is associated with cardiac arrhythmia on electrocardiography (ECG).

METHOD

The study included patients with hypertension whose blood pressure values were taken under control with optimal medical treatment. Arterial stiffness and CAVI were measured using the vascular scanning system VaSera VS-1000. The patients were divided into two groups as CAVI<9 and CAVI≥9. Ventricular repolarization markers QT and QTc intervals, Tp-e interval, and Tp-e/QT and Tp-e/QTc ratios were measured using 12‑lead ECG.

RESULTS

Tp-e interval (78.7 ± 10.3 vs. 63.6 ± 9.1, p < 0.001), Tp-e/QT ratio (0.018 ± 0.02 vs. 0.015 ± 0.02, p < 0.001), and Tp-e/QTc ratio (0.17 ± 0.02 vs. 0.14 ± 0.04, p = 0.025) were statistically significantly higher in the CAVI≥9 group compared to the CAVI<9 group. In the prediction of patients in the CAVI≥9 group, Tp-e interval had an area under the curve value of 0.862 (0.784-0.940, p < 0.001) at the cut-off point of >72.5 msec, indicating a statistically significant result. Left CAVI and right CAVI were found to be significantly correlated with Tp-e interval (r = -0.650, p < 0.001 and r = -0.663, p < 0.001, respectively).

CONCLUSION

We found that elevated CAVI values were associated and positively correlated with prolonged Tp-e interval values in patients with hypertension. Patients with elevated CAVI values should be followed up closely to prevent cardiac arrhythmic events.

Osteogenic Circulating Endothelial Progenitor Cells are Associated with Vascular Aging of the Large Arteries in Rheumatoid Arthritis

Background and Aim

Rheumatoid arthritis is associated with both abnormal bone metabolism and accelerated vascular aging but a mechanistic link was lacking. This study aims to investigate the role of osteocalcin (OCN)-expressing circulating endothelial progenitor cells (EPCs) in vascular aging, as determined by arterial calcifications in rheumatoid arthritis.

Methods

We performed flow cytometry studies in 145 consecutive patients with rheumatoid arthritis to determine osteogenic circulating levels of OCN-positive (OCN+) CD34+KDR+ and OCN+CD34+ versus conventional early EPC CD34+CD133+KDR+. Total calcium load of the thoracic aorta (ascending plus descending) and the carotid arteries were assessed by non-contrast computed tomography (CT) and contrast CT angiography.

Results

Osteogenic EPCs OCN+CD34+KDR+ (P = 0.002) and OCN+CD34+ (P = 0.001), together with clinical parameters of age, history of hypertension, systolic blood pressure, serum levels of triglycerides, HbA1c and creatinine, use of leflunomide and brachial-ankle pulse-wave velocity (all P < 0.05), were associated with the clustered presence of aortic and carotid calcification. Multivariable analyses revealed that circulating OCN+CD34+KDR+ (B = 14.4 [95% CI 4.0 to 24.8], P = 0.007) and OCN+CD34+ (B = 9.6 [95% CI 4.9 to 14.3], P < 0.001) remained independently associated with increased aortic calcium load. OCN+CD34+ EPC (B = 0.8 [95% CI 0.1 to 1.5], P = 0.023), but not OCN+CD34+KDR+ EPC (B = 1.2 [95% CI −0.2 to 2.6], P = 0.09), was further independently associated with carotid calcium load. In comparison, conventional early EPC CD34+CD133+KDR+ had no significant association with aortic or carotid calcium load (P = 0.46 and 0.88, respectively).

Conclusion

Circulating level of osteogenic EPC is associated with increased vascular aging in terms of calcification of the large arteries in patients with rheumatoid arthritis. The findings may suggest a role of the bone-vascular axis underlying vascular aging in rheumatic diseases. Further research is needed to characterize the mechanistic links and basis of these observations.

Epidemiology and Outcomes Associated with PR Prolongation

PR prolongation is defined primarily as delayed conduction through the AV node, but can also signify delayed electrical impulse propagation through any part of the conduction system. The prevalence of PR prolongation ranges from 1% to 5% in patients younger than 50 years, with increasing prevalence, after the sixth decade of life and in patients with organic heart disease. Contemporary studies have documented increased risk of atrial arrhythmias, heart failure, and mortality in patients with PR prolongation. Future studies are needed to more accurately risk stratify elderly patients with PR prolongation who may be at increased risk of adverse outcomes.

First-degree atrioventricular block in acute anterior myocardial infarction

BACKGROUND

There is paucity of data regarding the prognostic implications of first-degree atrioventricular block in patients with acute anterior myocardial infarction as a distinct group. The aim of this study was to elucidate the association of prolonged PR interval with hospital clinical outcomes in patients with treated with thrombolysis.

METHODS

Three hundred consecutive patients with a first acute anterior ST-segment elevation myocardial infarction undergoing thrombolysis between October 2017 and March 2018, were retrospectively enrolled in this study. They were divided into two groups based on PR interval on admission: PR interval ≤200 ms, and PR interval > 200 ms. Hospital mortality and complications were compared between the 2 groups.

RESULTS

Of the 300 patients, 26 (8.66%) had first-degree atrioventricular block on initial presentation. Overall, hospital death occurred in 20 (6.66%) patients. Patients with PR interval > 200 ms had a higher hospital mortality rate (26.9%) than those without (4.7%, p < 0.001). In multivariate Cox regression analysis, only left ventricular systolic function and PR interval were independent predictors of hospital mortality (odds ratio = 1.031; 95% confidence interval: 1.008-1.056, p = 0.009 for PR interval).

CONCLUSION

In patients with a first acute anterior ST-segment elevation myocardial infarction treated with thrombolysis, first-degree atrioventricular block was associated with increased hospital mortality and a worse prognosis.

Cumulative Rheumatic Inflammation Modulates the Bone-Vascular Axis and Risk of Coronary Calcification

Background

Rheumatic diseases are related to both abnormal bone turnover and atherogenesis, but a mechanistic link was missing.

Methods and Results

We investigated the effect of cumulative rheumatic inflammation (CRI) on risk of coronary calcification in a retrospective cohort of 145 rheumatoid arthritis patients. A time‐adjusted aggregate CRI score was derived by conglomerating all quarterly biomarker encounters of serum C‐reactive protein over 60 months immediately preceding computed tomography coronary angiography. Flow cytometry was performed to measure the osteocalcin‐positive (OCN⁺) CD34⁺KDR⁺ and OCN⁺CD34⁺ circulating endothelial progenitor cells (EPCs). Conventional early circulating EPCs CD34⁺CD133⁺KDR⁺ was determined. Coronary calcification was defined as any Agatston score >0. 50% of patients (n=72/145) had coronary calcification. CRI score was associated with presence of coronary calcification (P=0.004) (multivariable‐adjusted: highest versus lowest quartile: odds ratio=5.6 [95% CI 1.1–28.9], P=0.041). Receiver operating characteristics curve revealed divergent behavior of OCN‐expressing circulating EPCs (OCN⁺CD34⁺EPCs: area under the curve=0.60, P=0.034; OCN⁺CD34⁺KDR⁺EPCs: area under the curve=0.59, P=0.053, positive predictors) versus conventional early EPCs (CD34⁺CD133⁺KDR⁺: area under the curve=0.60, P=0.034, negative predictor) for coronary calcification, which persisted after multivariable adjustments (OCN⁺CD34⁺KDR⁺ [>75th percentile]: odds ratio=7.2 [95% CI 1.8–27.9], P=0.005; OCN⁺CD34⁺EPCs [>75th percentile]: odds ratio=6.0 [95% CI 1.5–23.3], P=0.010; CD34⁺CD133⁺KDR⁺ [>75th percentile: odds ratio=0.3 [95% CI 0.1–1.0], P=0.053). Intriguingly, the CRI score was associated with increased OCN⁺CD34⁺EPCs (highest versus lowest quartile: B=+25.6 [95% CI 0.8–50.5] [×10³/mL peripheral blood], P=0.043), but reduced CD34⁺CD133⁺KDR⁺EPCs (highest versus lowest quartile: B=−16.2 [95% CI −31.5 to −0.9], P=0.038).

Conclusions

Preceding 60 months of CRI is associated with increased risk of coronary calcification and altered OCN expression in circulating EPCs.

Osteogenic circulating endothelial progenitor cells are linked to electrocardiographic conduction abnormalities in rheumatic patients

BACKGROUND

Osteogenic circulating endothelial progenitor cells (EPC) play a pathogenic role in cardiovascular system degeneration through promulgating vasculature calcification, but its role in conduction disorders as part of the cardiovascular degenerative continuum remained unknown.

AIM

To investigate the role of osteocalcin (OCN)-expressing circulating EPCs in cardiac conduction disorders in the unique clinical sample of rheumatoid arthritis (RA) susceptible to both abnormal bone metabolism and cardiac conduction disorders.

METHODS

We performed flow cytometry studies in 134 consecutive asymptomatic patients with rheumatoid arthritis to derive osteogenic circulating OCN-positive (OCN+) CD34+KDR+ vs. CD34+CD133+KDR+ conventional EPC. Study endpoint was the prespecified combined endpoint of electrocardiographic conduction abnormalities.

RESULTS

Total prevalence of cardiac conduction abnormality was 9% (n = 12). All patients except one had normal sinus rhythm. One patient had atrial fibrillation. No patient had advanced atrioventricular (AV) block. Prevalence of first-degree heart block (>200 ms), widened QRS duration (>120 ms) and right bundle branch block were 6.7%, 2.1%, and 2.2% respectively. Circulating osteogenic OCN⁺ CD34⁺ KDR⁺ EPCs were significantly higher among patients with cardiac conduction abnormalities (p = 0.039). Elevated OCN⁺ CD34⁺ KDR⁺ EPCs> 75th percentile was associated with higher prevalence of cardiac conduction abnormalities (58.3% vs. 20.02%, p = 0.003). Adjusted for potential confounders, elevated OCN⁺ CD34⁺ KDR⁺ EPCs> 75th percentile remained independently associated with increased risk of cardiac conduction abnormalities (OR = 4.4 [95%CI 1.2-16.4], p = 0.028). No significant relation was found between conventional EPCs CD34+CD133+KDR+ and conduction abnormalities (p = 0.36).

CONCLUSIONS

Elevated osteogenic OCN⁺ CD34⁺ KDR⁺ EPCs are independently associated with the presence of electrocardiographic conduction abnormalities in patients with rheumatoid arthritis, unveiling a potential novel pathophysiological mechanism.

PR interval prolongation in coronary patients or risk equivalent: excess risk of ischemic stroke and vascular pathophysiological insights

BACKGROUND

Whether PR prolongation independently predicts new-onset ischemic events of myocardial infarction and stroke was unclear. Underlying pathophysiological mechanisms of PR prolongation leading to adverse cardiovascular events were poorly understood. We investigated the role of PR prolongation in pathophysiologically-related adverse cardiovascular events and underlying mechanisms.

METHODS

We prospectively investigated 597 high-risk cardiovascular outpatients (mean age 66 ± 11 yrs.; male 67%; coronary disease 55%, stroke 22%, diabetes 52%) for new-onset ischemic stroke, myocardial infarction (MI), congestive heart failure (CHF), and cardiovascular death. Vascular phenotype was determined by carotid intima-media thickness (IMT).

RESULTS

PR prolongation >200 ms was present in 79 patients (13%) at baseline. PR prolongation >200 ms was associated with significantly higher mean carotid IMT (1.05 ± 0.37 mm vs 0.94 ± 0.28 mm, P = 0.010). After mean study period of 63 ± 11 months, increased PR interval significantly predicted new-onset ischemic stroke (P = 0.006), CHF (P = 0.040), cardiovascular death (P < 0.001), and combined cardiovascular endpoints (P < 0.001) at cut-off >200 ms. Using multivariable Cox regression, PR prolongation >200 ms independently predicted new-onset ischemic stroke (HR 8.6, 95% CI: 1.9-37.8, P = 0.005), cardiovascular death (HR 14.1, 95% CI: 3.8-51.4, P < 0.001) and combined cardiovascular endpoints (HR 2.4, 95% CI: 1.30-4.43, P = 0.005). PR interval predicts new-onset MI at the exploratory cut-off >162 ms (C-statistic 0.70, P = 0.001; HR: 8.0, 95% CI: 1.65-38.85, P = 0.010).

CONCLUSIONS

PR prolongation strongly predicts new-onset ischemic stroke, MI, cardiovascular death, and combined cardiovascular endpoint including CHF in coronary patients or risk equivalent. Adverse vascular function may implicate an intermediate pathophysiological phenotype or mediating mechanism.

Prolonged PR interval and risk of recurrence of atrial fibrillation after catheter ablation

It has been demonstrated that a prolonged PR interval is associated with an increased risk of AF. However, the impact of a prolonged PR interval on recurrence of paroxysmal atrial fibrillation (AF) after catheter ablation is not clear. A total of 112 patients with a prolonged PR interval (PR > 200 ms) (PPR group) and 112 age- and gender-matched control patients (on a 1:1 basis) with a normal PR interval (NPR group) were included in this study. AF recurrence was defined as the occurrence of confirmed atrial tachyarrhythmia lasting more than 30 seconds beyond 3 months after catheter ablation in the absence of any antiarrhythmic treatment. During a mean follow-up period of 10.9 ± 5.5 months (range, 3-18 months), 61 patients (27.2%) developed recurrence of AF. The recurrence rate was higher in the PPR group than in the NPR group (33.9% versus 20.5%, respectively; P = 0.018). Cox regression analysis with adjustment for age, body mass index, valvular heart disease, left atrial diameter, and pulmonary vein isolation identified only a prolonged PR interval as an independent predictor of recurrence of AF (hazard ratio, 1.81; 95% confidence interval, 1.07-3.05; P = 0.027). Patients with a prolonged PR interval were at an increased risk of AF recurrence after catheter ablation.

Prolongation of PR interval is associated with endothelial dysfunction and activation of vascular repair in high-risk cardiovascular patients

PURPOSE

Epidemiological studies showed that PR prolongation is associated with increased risk of adverse cardiovascular outcomes. We investigated the relations of PR interval with indices of vascular function and endothelial repair as the underlying mechanisms.

METHODS

The study comprised 348 high-risk patients with prior coronary artery disease, ischemic stroke, and/or diabetes mellitus recruited from medical outpatient clinics and 150 healthy subjects without such a history. PR interval was considered prolonged if >200 ms, as determined from resting 12-lead electrocardiogram. Vascular function was assessed by brachial flow-meditated dilatation (FMD) using high-resolution ultrasound. Circulating CD133(+)/KDR(+) endothelial progenitor cell (EPC) levels were measured by flow cytometry.

RESULTS

Among healthy subjects, PR interval was inversely associated with FMD (R = -0.20, P = 0.015), but not with the level of circulating CD133(+)/KDR(+) EPC (R = 0.05, P = 0.58). Among high-risk cardiovascular patients, PR prolongation >200 ms was more common compared with healthy subjects (45/348 (13 %) versus 4/150 (3 %), P < 0.001). PR interval was associated inversely with FMD (R = -0.14, P = 0.01) and positively with circulating CD133(+)/KDR(+) EPC level (R = +0.14, P = 0.009). Circulating CD133(+)/KDR(+) EPC level was significantly increased in patients with PR prolongation >200 ms (0.87 ± 0.37 versus 0.68 ± 0.42 (log, ×10(-3)/ml), P = 0.005). Adjusted for potential confounders, increased PR interval remained independently associated with increased CD133(+)/KDR(+) EPC by +0.002 (95 % confidence interval (CI) 0.000 to 0.004 (log, ×10(-3)/ml), P = 0.011) and depressed FMD (B = -0.014 %, 95 % CI -0.027 to -0.002, P = 0.026).

CONCLUSIONS

PR prolongation is associated with endothelial dysfunction and evidence of endothelial repair activation in patients with high cardiovascular risk.