The role of inflammation in the pathogenesis and treatment of arrhythmias

The pathogenesis of arrhythmias is complex and multifactorial. The role of inflammation in the pathogenesis of both atrial and ventricular arrhythmias (VA) has been explored. However, developing successful pharmacotherapy regimens based on those pathways has proven more of a challenge. This narrative review provides an overview of five common arrhythmias impacted by inflammation, including atrial fibrillation (AF), myocardial infarction, arrhythmogenic cardiomyopathy, cardiac sarcoidosis, and QT prolongation, and the potential role for anti-inflammatory therapy in their management. We identified arrhythmias and arrhythmogenic disease states with the most evidence linking pathogenesis to inflammation and conducted comprehensive searches of United States National Library of Medicine MEDLINE^® and PubMed databases. Although a variety of agents have been studied for the management of AF, primarily in an effort to reduce postoperative AF following cardiac surgery, no standard anti-inflammatory agents are used in clinical practice at this time. Although inflammation following myocardial infarction may contribute to the development of VA, there is no clear benefit with the use of anti-inflammatory agents at this time. Similarly, although inflammation is clearly linked to the development of arrhythmias in arrhythmogenic cardiomyopathy, data demonstrating a benefit with anti-inflammatory agents are limited. Cardiac sarcoidosis, an infiltrative disease eliciting an immune response, is primarily treated by immunosuppressive therapy and steroids, despite a lack of primary literature to support such regimens. In this case, anti-inflammatory agents are frequently used in clinical practice. The pathophysiology of arrhythmias is complex, and inflammation likely plays a role in both onset and duration, however, for most arrhythmias the role of pharmacotherapy targeting inflammation remains unclear.

Proarrhythmic electrophysiological and structural remodeling in rheumatoid arthritis

Chronic inflammatory disorders, including rheumatoid arthritis (RA), are associated with a twofold increase in the incidence of sudden cardiac death (SCD) compared with the healthy population. Although this is partly explained by an increased prevalence of coronary artery disease, growing evidence suggests that ischemia alone cannot completely account for the increased risk. The present review explores the mechanisms of cardiac electrophysiological remodeling in response to chronic inflammation in RA. In particular, it focuses on the roles of nonischemic structural remodeling, altered cardiac ionic currents, and autonomic nervous system dysfunction in ventricular arrhythmogenesis and SCD. It also explores whether common genetic elements predispose to both RA and SCD. Finally, it evaluates the potential dual effects of disease-modifying therapy in both diminishing and promoting the risk of ventricular arrhythmias and SCD.

Cardiovascular system changes in rheumatoid arthritis patients with continued low disease activity

Systemic inflammation and disease activity seem to contribute to excessive prevalence of cardiovascular (CV) diseases (CVDs) in patients with rheumatoid arthritis (RA). The objective of the study was to assess chosen CV parameters in RA patients who have continuous low disease activity. The study group consisted of 70 RA patients without known CVD and 33 healthy controls, of a comparable age. All RA patients had continued low disease activity (DAS28 ≤ 3.2) from 2 to 7 years. The groups were assessed for: blood pressure, serum amino-terminal pro-brain natriuretic peptide (NT-proBNP), carotid intima media thickness (cIMT), electrocardiography (ECG), ejection fraction (EJ) and diastolic dysfunction (E/A ratio) in echocardiography. In RA patients in comparison with controls, significantly greater values of cIMT [0.83 (0.21) vs 0.62 (0.1) mm, p < 0.001] were found, as well as higher incidence of atherosclerotic plaques [43 (61.4%) vs 10 (30.3%), p = 0.003], prolonged QTc interval [439.6 (23.7) vs 414.0 (27.9) ms, p < 0.001]. High or very high Systemic Coronary Risk Evaluation (SCORE) was found in 32.9% of patients with RA and increased serum NT-proBNP in 71.4%. The mean values of CV parameters (cIMT, E/A, NT-proBNP, SCORE) were associated with age, disease duration, rheumatoid factor (RF-IgM), erythrocyte sedimentation rate (ESR). The results of our study indicate, that RA with continued low disease activity is associated with atherosclerosis and heart dysfunction. Strong relationships were found between CV parameters and patients' age, disease duration. Deterioration of CV parameters was associated with higher DAS28, ESR, RF-IgM concentration and bone erosions.

Biologic drugs and arrhythmic risk in chronic inflammatory arthritis: the good and the bad

Increasing evidence indicates that patients with chronic inflammatory arthritis (CIA), including rheumatoid arthritis and spondyloarthropathies, have an increased risk of arrhythmic events, significantly contributing to the higher cardiovascular disease (CVD) morbidity and mortality observed in these subjects compared to the general population. Although the mechanisms accounting for such an arrhythmogenic substrate are not fully understood, the main role is probably played by chronic systemic inflammation, able to accelerate the development of structural CVD, as well as to directly affect cardiac electrophysiology. In the past decade, biologic therapies have revolutionized the treatment of CIA by highly enhancing the probability to effectively control disease activity and its systemic consequences, including cardiovascular involvement. Accordingly, accumulating data demonstrated that by potently inhibiting systemic inflammation, biologic drugs can reduce CVD progression and ameliorate arrhythmic risk parameters, with a putative beneficial impact on arrhythmia incidence. Nevertheless, a significant number of reports from clinical trials and postmarketing experience suggest that some of these medications, particularly TNF inhibitor monoclonal antibodies and rituximab, may in some circumstances precipitate arrhythmia occurrence, probably by acutely amplifying myocardial electric instability intrinsically associated with these diseases. In this review, we analyze the intricate link between biologic drugs and arrhythmias in CIA in the effort to identify which factors are involved in the fine-tuning of antiarrhythmic/pro-arrhythmic balance, and understand how this knowledge should be translated in the clinical practice to obtain the most favorable benefit-to-risk profile when biologic drugs are used in these patients.

Association between corrected QT interval and inflammatory cytokines in rheumatoid arthritis

OBJECTIVE

Corrected QT (QTc) interval predicts all-cause and cardiovascular mortality and may contribute to the increased mortality risk in rheumatoid arthritis (RA). Animal experiments have shown that proinflammatory cytokines [tumor necrosis factor (TNF)-α and interleukin 1 (IL-1)] can prolong cardiomyocyte action potential. We sought to determine whether elevations in circulating inflammatory cytokines were independently associated with QTc prolongation in patients with RA.

METHODS

One hundred twelve patients [median age 62 (interquartile range 17) yrs; 80 women (71%)] from a well-characterized RA cohort underwent baseline 12-lead electrocardiograms for QT interval measurement and contemporary blood sampling to assess concentrations of inflammatory markers including C-reactive protein (CRP), TNF-α, and interleukins (IL-1α, IL-1β, IL-6, IL-10). QTc was calculated using the Bazett (QTBAZ = QT ÷ √RR) and Framingham Heart Study (QTFHS = QT + 0.154 × [1 - RR]) heart rate correction formulas.

RESULTS

Inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-10) were positively correlated with QTBAZ (Spearman rank correlation coefficient rho = 0.199, 0.210, 0.222, 0.333; all p < 0.05). In multivariable regression analysis, these associations were all confounded by age except IL-10, where higher tertile groups were independently and positively associated with QTBAZ (β = 0.202, p = 0.023) and QTFHS (β = 0.223, p = 0.009) when compared to the lower tertile. CRP (per unit increase) was independently associated with QTBAZ (β = 0.278, p = 0.001), but not QTFHS.

CONCLUSION

To our knowledge, ours is the first study demonstrating a contemporary link between inflammatory cytokines and QT interval in humans. Our results suggest that a lower inflammatory burden may protect against QTc prolongation in patients with RA. However, further studies are required to confirm the effects of pro- and antiinflammatory cytokines on QTc interval.

Association between high sensitivity C-reactive protein, heart rate variability and corrected QT interval in patients with chronic inflammatory arthritis

BACKGROUND

The risk of sudden cardiac death is increased in chronic inflammatory arthritis, particularly rheumatoid arthritis (RA). To evaluate the putative effect of systemic inflammation on heart rate variability (HRV) and ventricular repolarization in chronic inflammatory arthritis, we analyzed in these patients the possible relationship among HRV parameters, QT interval, and high sensitivity C-reactive protein (hsCRP).

METHODS

One hundred-one patients with chronic inflammatory arthritis underwent a 15-minute ambulatory twelve-channel electrocardiogram-recording, to evaluate HRV and QT interval, as well as a venous withdrawal for hsCRP as an estimation of ongoing systemic inflammation.

RESULTS

In patients with chronic inflammatory arthritis, hsCRP is inversely correlated with HRV and directly with QTc duration, but while hsCRP is associated with HRV independently from any other investigated factor, the association between hsCRP and QTc seems to be an indirect consequence of the autonomic dysfunction itself. Within the whole cohort of patients, those subjects having elevated hsCRP levels displayed both a significant reduction in HRV and a prolongation of QTc with respect to patients with a normal hsCRP value. A similar, although less marked, degree of HRV depression and QTc prolongation was found in RA patients when compared to subjects with spondyloarthritis (SpA) and healthy controls.

CONCLUSIONS

These data provide evidence of a link between systemic inflammation and the arrhythmic risk in patients with chronic inflammatory arthritis, also putatively explaining, at least in part, how the different inflammatory load characterizing RA and SpA parallels the different risks of cardiovascular death in these two conditions.

The relationship between QT dispersion and exaggerated blood pressure response to exercise stress testing

This study was aimed to investigate sensitivity and specificity of QT dispersion (QTd) as a predictor of hypertensive response to peak exercise stress testing (EST). Fifty-nine patients were divided in to two groups (32 patients with exaggerated blood pressure response (EBPR) to EST group and 27 patients for normotensive group) and the EST was monitored. The QTd and corrected QT (QTc) intervals were still found to be significant predictors of EBPR (P < 0.05). In receiver operating characteristic (ROC) analysis, a level of QTd ≥ 40 predicted EBPR with 84% sensitivity and 74% specificity. According to the present data, QTd might be an important predictive marker for EBPR.

Cardiovascular and cerebrovascular diseases in ankylosing spondylitis: current insights

Patients with ankylosing spondylitis (AS) suffer from an increased cardiovascular (CV) risk. The evidence for increased atherosclerotic disease is nowadays convincing, while the precise contribution of the so-called AS-specific (related) cardiac manifestations toward the increased CV risk still needs to be determined. Such studies should be performed in the near future, since they might have clinical consequences-for example, mandatory echocardiographic screening of AS patients. There appears to be a clear contribution of the "traditional" CV risk factors, as well as the underlying chronic inflammatory process, to the increased atherosclerotic risk in AS. Furthermore, there is accumulating evidence for an etiological role of inflammation in the AS-related cardiac manifestations. Nowadays, CV risk management appears necessary for AS patients, and this should consist of, on the one hand, assessment and treatment, if necessary, of the "traditional" CV risk factors, and, on the other hand, effective suppression of the inflammatory process.