Impact of Improved Left Ventricular Systolic Function on the Recurrence of Ventricular Arrhythmia in Heart Failure Patients With an Implantable Cardioverter-Defibrillator

Risk of Appropriate Implantable Cardioverter-Defibrillator Therapies and Sudden Cardiac Death in Patients With Heart Failure With Improved Left Ventricular Ejection Fraction

BACKGROUND

The benefit of implantable cardioverter-defibrillator (ICD) therapy is controversial in patients who have heart failure with improved left ventricular ejection fraction (EF) to >35% after implantation (HFimpEF).

METHODS

Databases (Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar) were queried for studies in patients with ICD that reported the association between HFimpEF and arrhythmic events (AEs), defined as the combined incidence of ventricular arrhythmias, appropriate ICD intervention, and sudden cardiac death (primary composite end point).

RESULTS

A total of 41 studies and 38,572 patients (11,135 with HFimpEF, 27,437 with persistent EF ≤35%) were included; mean follow-up was 43 months. HFimpEF was associated with decreased AEs (odds ratio [OR] 0.39, 95% confidence interval [CI] 0.32 to 0.47; annual rate [AR] 4.1% vs 8%, p <0.01). Super-responders (EF ≥50%) had less risk of AEs than did patients with more modest reverse remodeling (EF >35% and <50%, OR 0.25, 95% CI 0.14 to 0.46, AR 2.7% vs 6.2%, p <0.01). Patients with HFimpEF who had an initial primary-prevention indication had less risk of AEs (OR 0.43, 95% CI 0.3 to 0.61, AR 5.1% vs 10.3%, p <0.01). Among patients with primary prevention who had never received appropriate ICD therapy at the time of generator change, HFimpEF was associated with decreased subsequent AEs (OR 0.26, 95% CI 0.12 to 0.59, AR 1.6% vs 4.8%, p <0.01). In conclusion, HFimpEF is associated with reduced, but not eliminated, risk for AEs in patients with ICDs. The decision to replace an ICD in subgroups at less risk should incorporate shared decision making based on risks for subsequent AEs and procedural complications.

ACR Appropriateness Criteria® Dyspnea-Suspected Cardiac Origin (Ischemia Already Excluded): 2021 Update

Dyspnea is the symptom of perceived breathing discomfort and is commonly encountered in a variety of clinical settings. Cardiac etiologies of dyspnea are an important consideration; among these, valvular heart disease (Variant 1), arrhythmia (Variant 2), and pericardial disease (Variant 3) are reviewed in this document. Imaging plays an important role in the clinical assessment of these suspected abnormalities, with usually appropriate procedures including resting transthoracic echocardiography in all three variants, radiography for Variants 1 and 3, MRI heart function and morphology in Variants 2 and 3, and CT heart function and morphology with intravenous contrast for Variant 3. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Distribution and prognostic impact of coronary artery disease and nonischemic cardiomyopathies in patients with electrical storm

BACKGROUND

The distribution and prognostic impact of coronary artery disease (CAD) in ES are still under debate.

METHODS

Consecutive ES patients with implantable cardioverter-defibrillator (ICD) were included retrospectively from 2002 to 2016. Three analyses were applied to characterize ES patients: (a) ES patients without CAD (non-CAD), (b) ES patients with CAD (CAD), and (c) diagnostic findings assessed by coronary angiography (CA) at the time of ES (immediate CA). CAD was compared with non-CAD ES patients, and progressive CAD was compared with stable CAD ES patients. The primary endpoint was all-cause mortality at 2.5 years. Secondary endpoints were the composite endpoint of first recurrent ventricular tachyarrhythmias and appropriate ICD therapies, and recurrence of ES (ES-R) at 2.5 years.

RESULTS

Within a total of 87 consecutive ES patients. CAD was present in more than two-thirds (67%). However, only 52% patients underwent immediate CA at the time of ES. Here, 84% had CAD, of which 39% revealed progressive CAD with the need of target vessel revascularization (TVR) or cardiac transplantation (n = 1). At long-term follow-up, neither the presence (or absence) of CAD (41% vs. 34%; log rank P = 0.708) nor of progressive CAD (33% vs. 26%; log rank P = 0.372) was associated with all-cause mortality at 2.5 years, and further secondary endpoints including the composite of recurrent ventricular tachyarrhythmias plus appropriate ICD therapies, or ES-R.

CONCLUSION

In ES patients, CAD was more common than non-CAD-related cardiac diseases, accompanied by an underinvestigated rate of CA despite increasing rates of progressive CAD. CAD had no prognostic impact in ES.

Ongoing Risk of Ventricular Arrhythmias and All-Cause Mortality at Implantable Cardioverter Defibrillator Generator Change: A Systematic Review and Meta-Analysis

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Prognostic impact of left ventricular ejection fraction in patients with electrical storm

OBJECTIVES

The study sought to assess retrospectively the prognostic impact of left ventricular ejection fraction (LVEF) in patients with electrical storm (ES).

BACKGROUND

Data regarding the prognostic impact of impaired LVEF in ES patients is rare.

METHODS

Consecutive patients presenting with ES from 2002 to 2016 were included retrospectively. Patients with LVEF ≤ 35% were compared to patients with LVEF > 35%. The primary prognostic endpoint was long-term all-cause mortality, and secondary endpoints were rates of in-hospital mortality, rehospitalization, major adverse cardiac events (MACE), and ES recurrences (ES-R) at long-term follow-up.

RESULTS

A total of 80 patients with ES were included at 2.5 years of follow-up. 69% of patients suffered from LVEF ≤ 35%. ES patients with LVEF ≤ 35% were associated with higher rates of the primary endpoint of all-cause mortality (53% versus 8%, log-rank p = 0.0001; HR 8.524; 95% CI 2.030-35.793, p = 0.003), as well as the secondary endpoints of MACE (53% versus 20%; log rank p = 0.011; HR 3.213, 95% CI 1.241-8.316, p = 0.016) and ES-R (35% versus 8%; log rank p = 0.019; HR 4.821, 95% CI 1.122-20.706, p = 0.034). Furthermore, ES patients with LVEF ≤ 35% showed higher rates of rehospitalization due to acute heart failure (24% versus 8%, statistical trend p = 0.096). Notably, ES patients with LVEF > 35% were associated with increased rates of rehospitalization due to ventricular tachycardia (36% versus 18%, statistical trend p = 0.083).

CONCLUSIONS

ES patients with LVEF ≤ 35% were associated with increased rates of all-cause mortality, MACE, ES-R and heart failure-related rehospitalization at long-term follow-up. This study evaluated retrospectively the prognostic impact of LVEF in patients with ES. LVEF ≤ 35% was associated with increased long-term all-cause mortality (53% versus 8%; HR 8.524; 95% CI 2.030-35.793, p = 0.003), MACE (53% versus 20%; HR 3.213, 95% CI 1.241-8.316, p = 0.016), and ES recurrences (35% versus 8%; HR 4.821, 95% CI 1.122-20.706, p = 0.034), while trends were observed for higher rates of heart-failure related rehospitalization (24% versus 8%, p = 0.096) and MACE (49% versus 28%; p = 0.081).

Characteristics and prognosis of heart failure with improved compared with persistently reduced ejection fraction: A systematic review and meta-analyses

Aims We assessed the clinical characteristics and prognosis of chronic heart failure patients with improved ejection fraction (HFIEF) compared with persistently reduced ejection fraction (HFpREF) after evidence-based therapy. Methods and results We performed a meta-analysis including 24 eligible observational studies comparing 2663 HFIEF (≥5% left ventricular ejection fraction (LVEF) improvement) versus 8355 HFpREF patients who received recommended drug therapy, cardiac resynchronization therapy and/or intracardiac defibrillator. LVEF was assessed at baseline and reassessed after 19 ± 19 months. The primary endpoints were all-cause mortality and appropriate shocks. The mean duration of follow-up was 39 ± 12 months. Among HFIEF patients, LVEF improved 16.3 percentage points (95% confidence interval 15.9-16.6, p < 0.0001). Compared with HFpREF patients, HFIEF patients had a comparable mean age (60.9 years vs. 62.4 years, p = 0.11), were more often women (33% vs. 25%), had a higher prevalence of non-ischaemic heart failure (58% vs. 53%), less diabetes (27% vs. 28%), higher systolic blood pressure (127.5 ± 9 vs. 122 ± 12 mmHg) and lower left ventricle end-diastolic diameter (64.1 ± 3.7 vs. 67.4 ± 4.9 mmHg), all p-values < 0.05. Absolute risk of all-cause mortality was lower in HFIEF (5.8%) compared with HFpREF (17.5%) with a risk ratio of 0.34 (95% confidence interval 0.28-0.41), p < 0.001. Risk of appropriate shocks was significantly lower in HFIEF versus HFpREF (risk ratio 0.58 (95% confidence interval 0.46-0.74), p < 0.001). Conclusion In heart failure patients, we identified several baseline characteristics in favour of an improved LVEF, in response to evidence based therapy. Patients with improved LVEF had significantly lower risks of mortality and appropriate shocks compared with patients with persistently reduced LVEF.

Shocks after implantable cardioverter-defibrillator implantation in idiopathic cardiomyopathy patients: a myocardial biopsy study

Prediction of follow-up shock is crucial to stratify patients with dilated cardiomyopathy (DCM) requiring implantable cardioverter defibrillator (ICD). The objective of the article is to assess the predictive value of endo-myocardial biopsy (EMB) towards ICD shock and follow-up mortality. A series of patients with DCM scheduled for ICD implantation underwent EMB to further determine the genesis of DCM. Presence of fibrosis and inflammation was documented and related to outcomes. A total of 240 patients were referred for ICD as primary (56%) and secondary (44%) prophylaxis. EMB showed myocardial fibrosis in 55.4%, inflammation in 55.7%, and viral genomic material in 60%. Median follow-up was 39 months (1-209). Appropriate and inappropriate shocks occurred in 29.2 and 20.4%. At logistic regression, determinants of appropriate shock were ICD indication for secondary prophylaxis (direct relationship: p = 0.009, OR 3.4, CI 1.3-8.8) and presence of inflammation at EMB (inverse relationship: p = 0.04, OR 0.4, CI 0.1-0.9). Moreover, the sole determinant of inappropriate shock was age at implant (inverse relationship: p = 0.003, OR = 0.9, CI 0.90-0.98). Overall mean estimated survival was 168 months and 5-year survival was 83%. Degree of improvement in LVEF% was the sole determinant of follow-up mortality (inverse relationship p = 0.02; HR = 0.9; CI 0.88-0.99). Present selection criteria for ICDs implant rely mainly on LVEF% that lacks sensitivity and specificity. EMB can identify the substrate of increased or reduced life-threatening arrhythmias. Presence of inflammation is a positive prognostic factor for reduced arrhythmogenic risk, independently by the ICD implantation indication.

Prediction of Both Electrical and Mechanical Reverse Remodeling on Acute Electrocardiogram Changes After Cardiac Resynchronization Therapy

BACKGROUND

The development of both electrical reverse remodeling and mechanical reverse remodeling (ERR+MRR) after cardiac resynchronization therapy (CRT) implantation could reduce the incidence of lethal arrhythmia, hence the prediction of ERR+MRR is clinically important.Methods and Results:Eighty-three patients (54 male; 67±12 years old) with CRT >6 months were enrolled. ERR was defined as baseline intrinsic QRS duration (iQRSd) shortening ≥10 ms in lead II on ECG after CRT, and MRR as improvement in LVEF ≥25% on echocardiography after CRT. Acute ECG changes were measured by comparing the pre-implant and immediate post-implant ECG. Ventricular arrhythmia episodes, including ventricular tachycardia and ventricular fibrillation, detected by the implanted device were recorded. Patients were classified as ERR only (n=12), MRR only (n=23), ERR+MRR (n=26), or non-responder (ERR- & MRR-, n=22). On multivariate regression analysis, difference between baseline intrinsic QRS and paced QRS duration (∆QRSd) >35 ms was a significant predictor of ERR+MRR (sensitivity, 68%; specificity, 64%; AUC, 0.7; P=0.003), and paced QTc >443 ms was a negative predictor of ERR+MRR (sensitivity, 78%; specificity, 60%; AUC, 0.7; P=0.002). On Cox proportional hazard modeling, ERR+MRR may reduce risk of ventricular arrhythma around 70% compared with non-responder (HR, 0.29; 95% CI: 0.13-0.65).

CONCLUSIONS

Acute ECG changes after CRT were useful predictors of ERR+MRR. ERR+MRR was also a protective factor for ventricular arrhythmia.