Improvement of left ventricular ejection fraction in revascularized postmyocardial patients: indication for statistical fallacy

Revascularization and Left Ventricular Dysfunction for ICD Eligibility

Common triggers for sudden cardiac death (SCD) are transient ischemia, hemodynamic fluctuations, neurocardiovascular influences, and environmental factors. SCD occurs rapidly when sinus rhythm degenerates into ventricular tachycardia (VT) and/or ventricular fibrillation (VF), followed by asystole. Such progressive worsening of the cardiac rhythm is in most cases observed in the setting of ischemic heart disease and often associated with advanced left ventricular (LV) impairment. Revascularization prevents negative outcomes including SCD and heart failure (HF) due to LV dysfunction (LVD). The implantable cardioverter-defibrillator (ICD) on top of medical therapy is superior to antiarrhythmic drugs for patients with LVD and VT/VF. The beneficial effects of ICD have been demonstrated in primary prevention of SCD as well. However, yet debated is the temporal management for patients with LVD who are eligible to ICD prior to revascularization, either through percutaneous or surgical approach. Restoration of coronary blood flow has a dramatic impact on adverse LV remodeling, while it requires aggressive long-term antiplatelet therapy, which might increase complication for eventual ICD procedure when percutaneous strategy is pursued; on the other hand, when LV and/or multiorgan dysfunction is present and coronary artery bypass grafting is chosen, the overall risk is augmented, mostly in HF patients. The aims of this review are to describe the pathophysiologic benefits of revascularization, the studies addressing percutaneous, surgical or no revascularization and ICD implantation, as well as emerging defibrillation strategies for patients deemed at transient risk of SCD and/or at higher risk for transvenous ICD implantation.

Implantable Cardioverter Defibrillator in Primary and Secondary Prevention of SCD-What We Still Don't Know

Implantable cardioverter defibrillators (ICDs) are the cornerstone of primary and secondary prevention of sudden cardiac death (SCD) all around the globe. In almost 40 years of technological advances and multiple clinical trials, there has been a continuous increase in the implantation rate. The purpose of this review is to highlight the grey areas related to actual ICD recommendations, focusing specifically on the primary prevention of SCD. We will discuss the still-existing controversies strongly reflected in the differences between the international guidelines regarding ICD indication class in non-ischemic cardiomyopathy, and also address the question of early implantation after myocardial infarction in the absence of clear protocols for patients at high risk of life-threatening arrhythmias. Correlating the insufficient data in the literature for 40-day waiting times with the increased risk of SCD in the first month after myocardial infarction, we review the pros and cons of early ICD implantation.

Optimal Timing of Cardioverter-Defibrillator Implantation in Patients with Left Ventricular Dysfunction after Acute Myocardial Infarction

Background

Prevention of sudden cardiac death (SCD) early after acute myocardial infarction (AMI) is still a challenge, without clear recommendations in spite of the high incidence of life-threatening ventricular arrhythmias, as implantable cardiac defibrillator (ICD) placement is not indicated in the first 40 days after an AMI; this timing is aleatory and it is owed to fact that the two pivotal studies for evaluation of ICDs in primary prevention, MADIT and MADIT II, excluded the patients within three, respectively four weeks after AMI.

Methods

We conducted a retrospective, single-center study that included 77 patients with AMI. All patients were monitored by continuous ECG in the first week after the event. Transthoracic echocardiography was performed at discharge and 40 days after the event. Patients with ejection fraction of 35% or less as assessed by 2D echocardiography 40 days after the MI, which received an ICD for the primary prevention of SCD, were included in the study. The subjects were followed for a median of 38 months, by means of device interrogation and echocardiography.

Results

We divided our patients into two groups: in the first group, with left ventricular ejection fraction (LVEF) under 30% after MI, all patients remained in the reduced ejection fraction heart failure category, with an increase from an initial mean of 18.93 ± 4.99% to a mean of 22.18 ± 4.53% after a period of 40 days; we obtained a positive and statistically significant correlation (p < 0.001 and r - 0.547), and all patients presented indication of ICD implant 40 day after MI. In the second group with LVEF between 30% and 35% after MI, the mean LVEF increased from an initial mean of 31.73 ± 1.33% to a mean of 32.33 ± 1.49% after a period of 40 days. A statistically significant correlation (p - 0.02 and r - 0.78) was obtained, although 3 patients presented a LVEF over 35% at 40 days post-MI. Most of the ICD therapies (14.54%) appeared in patients with LVEF < 30% and these patients also presented a higher percentage of NSVT at initial ECG monitoring (54% vs. 50%) and NSVT at ICD interrogation (80% vs. 66.7%); statistical significance was not reached - p > 0.05. The majority of the ICD therapies (11.9% from 13.4%) appeared in patients with NSVT at initial ECG monitoring; also, these presented an increased number of NSVT at ICD interrogation (77.6% vs. 6%) when compared to patients without VT detection at the initial ECG monitoring. Still, statistical significance was not reached - p > 0.15.

Conclusions

The patients could benefit from ICD implant earlier than stated in the actual guidelines, since there are insufficient data in the literature for the waiting time of 40 days. Correlated with the increased risk of SCD in the first months post myocardial infarction, the present study proves the benefit of early ICD implantation considering that all our patients with a low ejection fraction immediately after infarction remained in the same category and the great majority (96.1%) required the implantation of an ICD after 40 days. Thus, we could avoid exposing our patients at risk of SCD for an unnecessary prolonged period, and choose early ICD implantation.

A review of the Surgical Treatment for Ischemic Heart Failure trial

Optimal treatment for patients with ischemic heart disease and severe left ventricular dysfunction is a debatable subject in the literature. The largest and only trial on the subject so far is the Surgical Treatment for Ischemic Heart Failure trial. This trial compared coronary artery bypass grafting with optimal medical treatment in one arm versus coronary artery bypass grafting with surgical ventricular restoration in the second arm. Recently, the 10-year follow-up data of various subsets of the trial have been published. This study reviews various pertinent clinical issues related to the trial and its sub-studies and their relevance in routine modern-day clinical practice.

Intervention Treatment for Myocardial Infarction With Tai Chi: A Systematic Review and Meta-analysis

OBJECTIVE

To assess the efficacy of Tai Chi (TC) in patients with myocardial infarction and provide up-to-date evidence for its application.

DATA SOURCES

Three English databases (PubMed, Embase, and Cochrane Central Register of Controlled Trials) and 3 Chinese databases (China Knowledge Resource Integrated, Wanfang, Weipu) were screened for the time period between January 1, 1976 and May 31, 2019.

STUDY SELECTION

Seven randomized and controlled experiments were included.

DATA EXTRACTION

Two independent researchers under 2 independent advisors extracted and classified the data from all relevant studies based on the prespecified inclusion criteria and rules for data extraction.

DATA SYNTHESIS

A total of 615 patients were included in this study. The TC group was comprised of 294 patients, and the control group included 261 patients. The results revealed that TC has significant effects on the outcomes of the 6-minute walk (standardized mean difference, 1.30; 95% confidence interval, 0.50-2.11) and left ventricular ejection fraction (standardized mean difference, 1; 95% confidence interval, 0.43-1.57) compared with no or low-density exercise. Also, TC positively affected the quality of life, pro-B type natriuretic peptide, and short form-36. However, TC did not significantly affect activities of daily living (P=.060), sense of coherence-13 (P=.057) and N-terminal-pro-brain natriuretic peptide (P=.081). A moderate to high heterogeneity was observed across all comparisons.

CONCLUSIONS

Compared with no exercise or other types of low-intensity physical activities, TC improved the outcome of the 6-minute walk, left ventricular ejection fraction, quality of life, and short form-36 scores, but reduced the outcome of pro-B type natriuretic peptide in patients with myocardial infarction. Therefore, TC could be an effective exercise option for cardiac rehabilitation. More research should be done to identify the effects of TC on academic functioning and to determine ways of motivating patients to use preventive TC interventions.

Sacubitril/Valsartan Improves Left Ventricular Ejection Fraction and Reverses Cardiac Remodeling in Taiwanese Patients with Heart Failure and Reduced Ejection Fraction

Background

The angiotensin receptor-neprilysin inhibitor sacubitril/valsartan is known to improve outcomes of cardiac death and hospitalization due to heart failure in patients with heart failure and reduced ejection fraction (HFrEF). However, data on improvements in ejection fraction after using sacubitril/valsartan are still lacking in Taiwan.

Methods

We conducted this prospective, single armed, observation cohort study to evaluate changes in left ventricular ejection fraction (LVEF) in patients with heart failure and reduced LVEF treated with sacubitril/valsartan. This was an all-comer study. We prescribed sacubitril/valsartan as both first-line and second-line therapy to every eligible patient regardless of whether they were already on standard therapy or newly-diagnosed with HFrEF. The primary outcome was improvements in LVEF. We also collected data about changes in left ventricular chamber size, blood pressure, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and renal function according to serum creatinine level.

Results

During March 2016 to April 2018, 93 patients were enrolled. The mean LVEF improved from 35 ± 6.1% to 50 ± 8.8% at 6 months use of sacubitril/valsartan (p < 0.001). The left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left atrial diameter all decreased. The average NT-proBNP level decreased from 6379 pg/mL to 1661 pg/dL.

Conclusions

Sacubitril/valsartan demonstrated a significant effect in improving LVEF, left ventricular reverse remodeling, and reduction of NT-proBNP in this Taiwanese cohort.

Impact of LDB3 gene polymorphisms on clinical presentation and implantable cardioverter defibrillator (ICD) implantation in Chinese patients with idiopathic dilated cardiomyopathy

OBJECTIVE

Mutations in LIM domain binding 3 (LDB3) gene cause idiopathic dilated cardiomyopathy (IDCM), a structural heart disease with a complicated genetic background. However, the association of polymorphisms in the LDB3 gene with susceptibility to IDCM in Chinese populations remains unexplored as dose the impact on clinical presentation.

METHODS

We sequenced all exons and the adjacent part of introns of the LDB3 gene in 159 Chinese Han IDCM patients and 247 healthy controls. Then we detected the distribution of polymorphisms in the LDB3 gene in all participants and assessed their associations with risk of IDCM. Additionally, we conducted a stratified genotype-phenotype correlation analysis.

RESULTS

The A allele of rs4468255 was significantly associated with IDCM (P<0.01). The rs4468255, rs11812601, rs56165849, and rs3740346 were also associated with diastolic blood pressure (DBP) and left ventricular ejection fraction (LVEF) (P<0.05). Notably, a higher frequency of rs4468255 polymorphism was observed in implantable cardioverter defibrillator (ICD) recipients under a recessive model (P<0.01), whereas the significant association disappeared after adjusting for potential confounders. However, in the dominant model, notable correlations could only be observed after adjusting for multi parameters.

CONCLUSIONS

The rs4468255 was significantly correlated with IDCM of Chinese Han population. A allele of rs4468255 is higher in IDCM patients with ICD implantation, suggesting the influence of genetic background in the generation of this response. In addition, rs11812601, rs56165849, and rs3740346 in LDB3 show association with brain natriuretic peptide, DBP, and LVEF levels in patients with IDCM but did not show any association with IDCM susceptibility.

The importance of return to work: How to achieve optimal reintegration in ACS patients

The vocational reintegration of patients after an acute coronary syndrome is a crucial step towards complete convalescence from the social as well as the individual point of view. Return to work rates are determined by medical parameters such as left ventricular function, residual ischaemia and heart rhythm stability, as well as by occupational requirement profile such as blue or white collar work, night shifts and the ability to commute (which is, in part, determined by physical fitness). Psychosocial factors including depression, self-perceived health situation and pre-existing cognitive impairment determine the reintegration rate to a significant extent. Patients at risk of poor vocational outcomes should be identified in the early period of rehabilitation to avoid a reintegration failure and to prevent socio-professional exclusion with adverse psychological and financial consequences. A comprehensive healthcare pathway of acute coronary syndrome patients is initiated by cardiac rehabilitation, which includes specific algorithms and assessment tools for risk stratification and occupational restitution. As the first in its kind, this review addresses determinants and legal aspects of reintegration of patients experiencing an acute coronary syndrome, and offers practical advice on reintegration strategies particularly for vulnerable patients. It presents different approaches and scientific findings in the European countries and serves as a recommendation for action.

The use of echocardiographic and clinical data recorded on admission to simplify decision making for elective percutaneous coronary intervention: a prospective cohort study

BACKGROUND

Coronary artery disease (CAD), a leading cause of mortality, affects patient health-related quality of life (HRQoL). Elective percutaneous coronary interventions (ePCIs) are usually performed to improve HRQoL of CAD patients. The aim of this study was to design models using admission data to predict the outcomes of the ePCI treatments on the patients' HRQoL.

METHODS

This prospective cohort study was conducted with CAD patients who underwent ePCIs at the King Abdullah University Hospital in Jordan from January 2014 through May 2015. Six months after their ePCI procedures, the participants completed the improved MacNew (QLMI-2) questionnaire, which was used for evaluating three domains (physical, emotional and social) of HRQoL. Multivariate linear regression was used to design models to predict the three domains of HRQoL from echocardiographic findings and clinical data that are routinely measured on admission.

RESULTS

The study included 239 patients who underwent ePCIs and responded to the QLMI-2 questionnaire. The mean age (± standard deviation) of the participants was 55.74 ± 11.84 years, 54.58 ± 11.37 years for males (n = 174) and 59.11 ± 12.49 years for females (n = 65). The average scores for physical, emotional and social HRQoL were 4.38 ± 1.27, 4.4 ± 1.11, and 4.37 ± 1.32, respectively. Out of the 42 factors inputted to the models to predict HRQoL scores, 10, 9, and 9 factors were found to be significant determinants for physical, emotional and social domains, respectively, with adjusted coefficients of determination of 0.630, 0.604 and 0.534, respectively. Basophil levels on admission showed a significant positive correlation with the three domains of HRQoL, while aortic root diameter showed a negative correlation. Scores for the three domains were significantly lower in women than in men. Hypertensive and diabetic patients had significantly lower HRQoL scores than patients without hypertension and diabetes.

CONCLUSION

The prediction of HRQoL scores 6 months after an ePCI is possible based on data acquired on admission. The models developed here can be used as decision-making tools to guide physicians in identifying the efficacy of ePCIs for individual patients, hence decreasing the rate of inappropriate ePCIs and reducing costs and complications.