Anemia and the Risk of Life-threatening Ventricular Tachyarrhythmias from the Israeli Implantable Cardioverter Defibrillator Registry

Development of a Clinical Risk Score for Prediction of Life-Threatening Arrhythmia Events in Patients with ST Elevated Acute Coronary Syndrome after Primary Percutaneous Coronary Intervention

ST-elevated acute coronary syndrome (STEACS) is a serious condition requiring timely treatment. Reperfusion with primary percutaneous coronary intervention (pPCI) is recommended and preferred over fibrinolysis. Despite its efficacy, lethal complications, such as life-threatening arrhythmia (LTA), are common in post-PCI patients. Although various risk assessment tools were developed, only a few focus on LTA prediction. This study aimed to develop a risk score to predict LTA events after pPCI. A risk score was developed using a retrospective cohort of consecutive patients with STEACS who underwent pPCI at Chiangrai Prachanukroh Hospital from January 2012 to December 2016. LTA is defined as the occurrence of malignant arrhythmia that requires advanced cardiovascular life support (ACLS) within 72 h after pPCI. Logistic regression was used for model derivation. Among 273 patients, 43 (15.8%) developed LTA events. Seven independent predictors were identified: female sex, hemoglobin < 12 gm/dL, pre- and intra-procedural events (i.e., respiratory failure and pulseless arrest), IABP insertion, intervention duration > 60 min, and desaturation after pPCI. The LTA score showed an AuROC of 0.93 (95%CI 0.90, 0.97). The score was categorized into three risk categories: low (<2.5), moderate (2.5–4), and high risk (>4) for LTA events. The LTA score demonstrated high predictive performance and potential clinical utility for predicting LTA events after pPCI.

Predictive impacts of chronic kidney disease and cardiac sympathetic nervous activity on lethal arrhythmic events in chronic heart failure

Background

The clinical implications of chronic kidney disease (CKD) and cardiac sympathetic nervous activity (CSNA) regarding lethal arrhythmic events have not yet been fully elucidated in patients with chronic heart failure (CHF). We hypothesized that the combination of CKD and abnormal CSNA, assessed by ¹²³I‐metaiodobenzylguanidine (¹²³I‐MIBG) scintigraphy, may provide useful prognostic information for lethal arrhythmic events.

Methods

We studied 165 consecutive hospitalized CHF patients without dialysis. Cardiac ¹²³I‐MIBG scintigraphy was performed in a clinically stable condition, and abnormal CSNA was defined as a late heart‐to‐mediastinum ratio of <1.6. CKD was defined as an estimated glomerular filtration rate of <60 ml/min/1.73 m². We then investigated the incidence of lethal arrhythmic events (sustained ventricular tachyarrhythmia, appropriate implantable cardioverter‐defibrillator therapy, or sudden cardiac death).

Results

During a median follow‐up of 5.3 years, lethal arrhythmic events were observed in 40 patients (24.2%). The patients were divided into four groups according to the presence of CKD and CSNA abnormality: non‐CKD/normal CSNA (n = 52), CKD/normal CSNA (n = 39), non‐CKD/abnormal CSNA (n = 33), and CKD/abnormal CSNA (n = 41). Kaplan–Meier analysis showed that CKD/abnormal CSNA had the highest event rate (log‐rank p = .004). Additionally, the Cox proportional hazard analysis revealed that CKD/abnormal CSNA was a predictor for lethal arrhythmic events compared with non‐CKD/normal CSNA (hazard ratio, 5.368, p = .001). However, the other two groups did not show significant differences compared with the non‐CKD/normal CSNA group.

Conclusions

The combination of CKD and abnormal CSNA, assessed by ¹²³I‐MIBG scintigraphy, had a high predictive value for lethal arrhythmic events in patients with CHF.

Effect of Anemia on the Prognosis of Patients with Ventricular Tachyarrhythmias

This study evaluates the prognostic impact of anemia in patients presenting with ventricular tachyarrhythmias. The present longitudinal, observational, registry-based, monocentric cohort study included retrospectively all consecutive patients presenting with ventricular tachyarrhythmias on admission from 2002 to 2016. Anemic patients (hemoglobin levels <12.0 g/dl) were compared with non-anemic patients (hemoglobin levels ≥12.0 g/dl). The primary endpoint was all-cause mortality at 2.5 years. Secondary endpoints were cardiac death at 24 hours, all-cause mortality at index hospitalization, and the composite endpoint of cardiac death at 24 hours, recurrent ventricular tachyarrhythmias, and appropriate ICD therapies at 2.5 years. A total of 2,184 consecutive patients were included, of whom 30% were anemic and 70% non-anemic. Anemia was associated with the primary endpoint of all-cause mortality at 2.5 years (65% vs 29%, p = 0.001; HR = 2.441; 95% CI 2.086 to 2.856), cardiac death at 24 hours (26% vs 11%, p = 0.001), all-cause mortality at index hospitalization (45% vs 20%, p = 0.001), and the composite endpoint (35% vs 27%, p = 0.001; HR = 2.923; 95% CI 2.564 to 4.366). After multivariable adjustment, anemia was no longer associated with the composite endpoint. Predictors of adverse prognosis for anemics were CKD (HR = 2.191), LVEF <35% (HR = 1.651), cardiogenic shock (HR = 1.591), CPR (HR = 1.460), male gender (HR = 1.379), and age (HR = 1.017). In conclusion, anemic patients presenting with ventricular tachyarrhythmias were associated with increased long-term mortality at 2.5 years but not with the composite arrhythmic endpoint at 2.5 years. Predictors of adverse prognosis at 2.5 years were CKD, LVEF <35%, cardiogenic shock, CPR, male gender, and age.