Predictors of Subcutaneous Implantable Cardioverter-Defibrillator Shocks and Prognostic Impact in Patients With Structural Heart Disease.

BACKGROUND: In this study we aimed to assess long-term outcomes in subcutaneous implantable cardioverter-defibrillator (S-ICD) recipients with structural heart disease by focussing especially on shock incidence, predictors, and associated prognoses. METHODS: In this multicenter registry‒based study, we retrospectively included all patients who underwent S-ICD implantation at 3 tertiary centers. The prognostic impact of S-ICD shock was assessed with a composite outcome that included all-cause death and hospitalisation for heart failure. RESULTS: A total of 351 patients with underlying cardiomyopathy were included in the investigation. Using multivariable Fine and Gray regression models, secondary prevention, left ventricular ejection fraction (LVEF), conditional shock threshold, and QRS duration appeared to be independent predictors of appropriate S-ICD shock occurrence. In the multivariate Cox regression model adjusted for age, baseline LVEF, underlying cardiomyopathy subtype, New York Heart Association class, and appropriate shocks were significantly associated with increased composite prognostic outcome risk (hazard ratio [HR], 2.61; 95% confidence interval [CI], 1.21-5.65; P = 0.014), whereas inappropriate shocks were not (HR, 1.35; 95% CI, 0.75-4.48; P = 0.18). The analysis of each component of the composite prognostic outcome highlighted that the occurrence of appropriate shocks was associated with an increased risk of hospitalisation for heart failure (HR, 3.10; 95% CI, 1.26-7.58; P = 0.013) and a trend for mortality (HR, 2.19; 95% CI, 0.78-6.16; P = 0.14). CONCLUSIONS: Appropriate S-ICD shocks were associated with a 3-fold increase in acute heart failure admission, whereas inappropriate shocks were not. Conditional shock threshold programming is an independent predictor of S-ICD shock, and its prognostic impact should be investigated further in patients with structural heart disease.

Clinical significance of electrocardiographic markers of myocardial damage prior to aortic valve replacement.

BACKGROUND: Pre-operative myocardial fibrosis and remodeling impact on outcomes after aortic valve replacement (AVR). We aimed at investigating the prognostic impact of preoperative electrocardiographic (ECG) markers of left ventricular (LV) myocardial damage, i.e. bundle branch block (BBB) and ECG strain pattern after (surgical or transcatheter) AVR for severe aortic stenosis (AS). METHODS: Between April 2008 and October 2017, we explored consecutive patients referred to our Heart Valve Clinic for first AVR for severe AS. Detailed pre-operative phenotyping and ECG analysis were performed. Patients were followed-up after AVR for major cardiac events (ME), i.e. cardiovascular death, cardiac hospitalization for acute heart failure and stroke. RESULTS: BBB and ECG strain were respectively observed in 13.5 and 21% of the 1122 patients included. These ECG markers identified a subgroup of older patients, with higher NYHA class and more advanced myocardial disease as detected by echocardiography, i.e. higher LV mass and lower LV ejection fraction, global longitudinal strain and integrated backscatter, than patients without ECG strain or BBB. ME occurred in 212 (18.6%) patients during a mean follow-up of 4.4 ± 1.5 years with higher incidence in case of ECG strain or BBB (HR 1.56, 95%CI 1.13-2.14, p = 0.006; HR 1.47, 95%CI 1.02-2.13, p = 0.04 respectively). The prognostic value of ECG strain remained significant after adjustment for age, diabetes and pre-operative LVEF. CONCLUSIONS: Pre-operative ECG markers of myocardial damage identify a subgroup of AS patients at high risk of post-AVR cardiovascular complications irrespective of other prognostic factors and should help the multiparametric staging of cardiac damage to guide AVR.

Pharmacotherapy in inherited and acquired ventricular arrhythmia in structurally normal adult hearts.

Introduction: Ventricular arrhythmias are often seen in association with structural heart disease. However, approximately a tenth of affected patients have apparently normal hearts, where such arrhythmias typically occur in young patients, are sometimes inherited and can occasionally lead to sudden cardiac death (SCD). Over the past two decades, increased understanding of the underlying pathophysiology resulted in improved targeted pharmacological therapy.Areas covered: This article reviews current knowledge regarding drug therapy for inherited arrhythmia syndromes (Brugada, early repolarization, long QT and short QT syndromes, and catecholaminergic polymorphic ventricular tachycardia), and acquired arrhythmias (idiopathic ventricular fibrillation, short-coupled torsade de pointes, outflow tract ventricular tachycardia, idiopathic left, papillary muscle and annular ventricular tachycardias).Expert opinion: In inherited arrhythmia syndromes, appropriate clinical and genetic diagnoses followed by proper selection and dosing of antiarrhythmic drugs are of utmost importance to prevent SCD, most often without the need of implantable cardioverter-defibrillators. In acquired arrhythmias, appropriate pharmacotherapy in selected patients can also provide symptomatic relief and avoid the need for invasive therapy. Further research is needed to develop novel antiarrhythmic drugs or targeted therapy to increase efficacy and limit side effects.

Epicardial fat amount is associated with the magnitude of left ventricular remodeling in aortic stenosis.

Both genetic and environmental factors interact to control left ventricular (LV) remodeling in the context of aortic stenosis (AS). Epicardial adipose tissue (EAT) is a specific visceral adipose tissue with paracrine properties in close contact with the myocardium. We sought to assess determinants of EAT amount and its association with the magnitude and pattern of LV remodeling in patients suffering from severe AS. Between January 2014 and September 2017, we prospectively explored consecutive patients referred to our Heart Valve Center for SAVR presenting with severe AS and normal left ventricular ejection fraction (> 50%). Comprehensive transthoracic echocardiography (TTE) including assessment of LV remodeling and EAT amount were performed. 202 patients were included. EAT was significantly larger in elderly, diabetic and obese patients. EAT thickness was correlated positively with indexed LV mass in AS (r2 = 0.21; p < 0.0001) as well as severe LV remodeling pattern. Importantly, this observation persisted after adjustment for other factors associated with LV remodeling (ß ± SE = 1.74 ± 0.34; p < 0.0001). Large amounts of EAT are positively and independently associated with more pronounced and severe LV remodeling in severe AS. Further exploration regarding the impact of functional properties of EAT on LV remodeling is required.

Peri-operative acute kidney injury upon cardiac surgery time-of-day.

BACKGROUND: A relevant morning-afternoon variation in ischemia-reperfusion (IR) insult after cardiac surgery has been demonstrated. We speculated that the biorhythm might also impact systemic reactions involved in acute kidney injury (AKI) following cardiac surgery. We aimed at investigating incidence, determinants and prognostic impact of AKI in a large cohort of patients referred for surgical aortic valve replacement (SAVR) according to surgery time-of-day. METHODS: Between 2009 and 2015, we explored consecutive patients referred to our Heart Valve Center (CHU Lille) for first SAVR. Patients undergoing morning and afternoon SAVR were matched into pairs by propensity score and followed for major events (ME) i.e. cardiovascular death, cardiac hospitalization for acute heart failure (HF) and post-operative myocardial infarction. AKI was defined using KDIGO classification. RESULTS: In the matched population (n = 596 patients), AKI occurred in 20% of patients. After multivariable adjustment, medical history of hypertension, pre-operative renal function impairment and cardio-pulmonary bypass duration were independent predictors of AKI onset. Post-operative AKI was significantly associated with increased occurrence of ME and specifically of cardiac hospitalization for HF (p = 0.0035 and p = 0.0071, respectively) during the 500 days following SAVR. Finally, AKI occurrence and severity were similar between morning and afternoon groups (p = 0.98 and p = 0.99, respectively). CONCLUSION: We showed that despite current high-quality patient management during and following SAVR, peri-operative AKI remains frequent, developing in 20% of patients, and clearly worsens mid-term post-operative outcomes. AKI more often develops in patients with pre-operative chronic kidney disease and long duration of cardiac surgery but is not influenced by surgery time-of-day.

Daytime variation of perioperative myocardial injury in cardiac surgery and its prevention by Rev-Erbα antagonism: a single-centre propensity-matched cohort study and a randomised study.

BACKGROUND: On-pump cardiac surgery provokes a predictable perioperative myocardial ischaemia-reperfusion injury which is associated with poor clinical outcomes. We determined the occurrence of time-of-the-day variation in perioperative myocardial injury in patients undergoing aortic valve replacement and its molecular mechanisms. METHODS: We studied the incidence of major adverse cardiac events in a prospective observational single-centre cohort study of patients with severe aortic stenosis and preserved left ventricular ejection fraction (>50%) who were referred to our cardiovascular surgery department at Lille University Hospital (Lille, France) for aortic valve replacement and underwent surgery in the morning or afternoon. Patients were matched into pairs by propensity score. We also did a randomised study, in which we evaluated perioperative myocardial injury and myocardial samples of patients randomly assigned (1:1) via permuted block randomisation (block size of eight) to undergo isolated aortic valve replacement surgery either in the morning or afternoon. We also evaluated human and rodent myocardium in ex-vivo hypoxia-reoxygenation models and did a transcriptomic analysis in myocardial samples from the randomised patients to identify the signalling pathway(s) involved. The primary objective of the study was to assess whether myocardial tolerance of ischaemia-reperfusion differed depending on the timing of aortic valve replacement surgery (morning vs afternoon), as measured by the occurrence of major adverse cardiovascular events (cardiovascular death, myocardial infarction, and admission to hospital for acute heart failure). The randomised study is registered with ClinicalTrials.gov, number NCT02812901. FINDINGS: In the cohort study (n=596 patients in matched pairs who underwent either morning surgery [n=298] or afternoon surgery [n=298]), during the 500 days following aortic valve replacement, the incidence of major adverse cardiac events was lower in the afternoon surgery group than in the morning group: hazard ratio 0·50 (95% CI 0·32-0·77; p=0·0021). In the randomised study, 88 patients were randomly assigned to undergo surgery in the morning (n=44) or afternoon (n=44); perioperative myocardial injury assessed with the geometric mean of perioperative cardiac troponin T release was significantly lower in the afternoon group than in the morning group (estimated ratio of geometric means for afternoon to morning of 0·79 [95% CI 0·68-0·93; p=0·0045]). Ex-vivo analysis of human myocardium revealed an intrinsic morning-afternoon variation in hypoxia-reoxygenation tolerance, concomitant with transcriptional alterations in circadian gene expression with the nuclear receptor Rev-Erbα being highest in the morning. In a mouse Langendorff model of hypoxia-reoxygenation myocardial injury, Rev-Erbα gene deletion or antagonist treatment reduced injury at the time of sleep-to-wake transition, through an increase in the expression of the ischaemia-reperfusion injury modulator CDKN1a/p21. INTERPRETATION: Perioperative myocardial injury is transcriptionally orchestrated by the circadian clock in patients undergoing aortic valve replacement, and Rev-Erbα antagonism seems to be a pharmacological strategy for cardioprotection. Afternoon surgery might provide perioperative myocardial protection and lead to improved patient outcomes compared with morning surgery. FUNDING: Fondation de France, Fédération Française de Cardiologie, EU-FP7-Eurhythdia, Agence Nationale pour la Recherche ANR-10-LABX-46, and CPER-Centre Transdisciplinaire de Recherche sur la Longévité.