Novel Imaging and Genetic Risk Markers in Takotsubo Syndrome

Takotsubo syndrome (TTS) is an increasingly recognized condition burdened by significant acute and long-term adverse events. The availability of novel techniques expanded the knowledge on TTS and allowed a more accurate risk-stratification, potentially guiding clinical management. The present review aims to summarize the recent advances in TTS prognostic evaluation with a specific focus on novel imaging and genetic markers. Parametric deformation analysis by speckle-tracking echocardiography, as well as tissue characterization by cardiac magnetic resonance imaging T1 and T2 mapping techniques, currently appear the most clinically valuable applications. Notwithstanding, computed tomography and nuclear imaging studies provided limited but promising data. A genetic predisposition to TTS has been hypothesized, though available evidence is still not sufficient. Although a genetic predisposition appears likely, further studies are needed to fully characterize the genetic background of TTS, in order to identify genetic markers that could assist in predicting disease recurrences and help in familial screening.

Assessing Atrial Fibrillation Substrates by P Wave Analysis: A Comprehensive Review

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Pharmacologic and non-pharmacologic rhythm control strategies impact on AF-related symptoms, while leaving largely unaffected the risk of stroke. Moreover, up to 20% of AF patients are asymptomatic during paroxysmal relapses of arrhythmia, thus underlying the need for early markers to identify at-risk patients and prevent cerebrovascular accidents. Indeed, non-invasive assessment of pre-clinical substrate changes that predispose to AF could provide early identification of at-risk patients and allow for tailored care paths. ECG-derived P wave analysis is a simple-to-use and inexpensive tool that has been successfully employed to detect AF-associated structural and functional atrial changes. Beyond standard electrocardiographic techniques, high resolution signal averaged electrocardiography (SAECG), by recording microvolt amplitude atrial signals, allows more accurate analysis of the P wave and possibly AF risk stratification. This review focuses on the evidence that support P wave analysis to assess AF substrates, predict arrhythmia relapses and guide rhythm-control interventions.

Prognostic implications of nonsustained ventricular tachycardia morphology in high-risk patients with hypertrophic cardiomyopathy

INTRODUCTION

The prognostic impact of nonsustained ventricular tachycardia (NSVT) morphology has never been explored in hypertrophic cardiomyopathy (HCM). In a single-center cohort of consecutive HCM patients implanted with an implanted cardioverter-defibrillator (ICD), we assessed NSVT morphology patterns and their prognostic implications.

METHODS

A cohort of consecutive HCM patients implanted with an ICD was followed from ICD implantation to last follow-up visit. Patients were assessed for NSVT as stored events in ICD memory. Ventricular tachycardias (VTs) were classified as monomorphic (MM) or polymorphic according to intracardiac electrogram morphology.

RESULTS

One hundred nine consecutive HCM patients (68 males; mean age: 45 ± 17 years) composed the study population. During follow-up (71 ± 48 months), 7 polymorphic NSVT in 4 patients and 370 MM NSVT in 42 patients were retrieved from ICD memory. Among patients with only MM NSVT, 19 (45%) had one morphology, 17 (41%) had two morphologies, 3 (7%) had three morphologies, and 3 (7%) had four morphologies. Patients with polymorphic NSVT had the highest risk of ICD interventions (HR, 5.04; 95% CI, 1.26-20.19; P = .02). A stepwise increase of the risk of ICD interventions in patients with two, three, and four NSVT morphologies was observed. Out of 16 patients with both NSVT and ICD-treated VTs, 13 (81%) had at least one ICD-treated VT with the same morphology of a previous long-lasting NSVT.

CONCLUSIONS

In high-risk HCM patients, the occurrence of polymorphic NSVT and of NSVT with multiple morphologies carries a high risk for ICD interventions. Sustained VTs tend to recur with the same morphology of previous long-lasting NSVTs.

The subcutaneous implantable cardioverter-defibrillator: Current trends in clinical practice between guidelines and technology progress

The subcutaneous implantable cardioverter defibrillator (S-ICD) is a valuable alternative to the conventional trans-venous ICD (TV-ICD) for the prevention of sudden cardiac death (SCD). Prospective registries showed that the S-ICD is safe and effective in treating ventricular tachyarrhythmias in high-risk patients without pacing indications. While in earlier studies patients implanted with S-ICDs were young and mostly affected by channelopathies, contemporary S-ICD cohorts include patients with severely impaired left ventricular function and significant comorbidities. This review focuses on S-ICD evidence-based use and highlights current gaps between guidelines recommendations and real-world clinical practice.

Safety and efficacy of anti-tachycardia pacing in patients with hypertrophic cardiomyopathy implanted with an ICD

BACKGROUND

In hypertrophic cardiomyopathy (HCM) patients implanted with an implantable cardioverter defibrillator (ICD), clinical outcomes of antitachycardia pacing (ATP) have been poorly explored. In a retrospective analysis of a cohort of consecutive HCM patients implanted with an ICD, we aimed to assess the efficacy, safety, and clinical value of ATP.

METHODS

The cohort of HCM patients implanted with a transvenous ICD and followed in our center was assessed for device intervention from implantation to last clinical follow-up.

RESULTS

Overall 77 patients (45 males; mean age: 46 ± 16 years) were analyzed. After 67 ± 41 months, 24 patients had 49 ventricular tachycardia/fibrillation (VT/VF) appropriately treated (5.8% per year). Among 39 monomorphic VTs, ATP was effective in 27 (success rate: 69%). Mean time from VT onset to ATP delivery was 9.1 ± 4.9 s. The only clinical variable improving ATP success was use of beta-blockers (81% vs 50%; P = .04). Out of 12 ineffectively treated VTs, one was immediately shocked, four self-terminated after 18 ± 12 s, and seven (18%) were accelerated to a new VT. ATP was also delivered for 27 of 42 inappropriately detected episodes and induced two de novo VTs (7%). In the per patient analysis, 14 out 77 (18%) patients had one or more appropriate and effective ATP (3.4% per year), and only six (8%; 1.4% per year) received more than one ATP.

CONCLUSION

ATP is moderately effective for the treatment of monomorphic VTs in HCM patients. However, the rate of appropriate ATP therapies is low, ATP is often prematurely delivered, and ATP-induced arrhythmia degeneration is of concern.

Autonomic cardiovascular control and cardiac arrhythmia in two pregnant women with hypertrophic cardiomyopathy: Insights from ICD monitoring

In women with hypertrophic cardiomyopathy (HCM), pregnancy prompts major changes in hemodynamic and cardiac autonomic function that may precipitate heart failure (HF) or increase the risk of cardiac arrhythmia. We report the clinical follow-up of two patients with non-obstructive HCM implanted with a cardioverter defibrillator (ICD) allowing for continuous analysis of heart rate (HR), heart rate variability (HRV) and cardiac arrhythmia throughout the entire course of pregnancy. Both patients experienced increased HR and decreased HRV from the early stages of pregnancy, which persisted until delivery. Premature ventricular contractions (PVCs) and runs of non-sustained ventricular tachycardia (NSVT) reached a peak in the second and third trimesters, concurrent with sympathetic hyperactivity. In one patient with baseline NYHA class II HF symptoms, increased PVCs and NSVT were consistent with the deterioration of HF, supporting the decision to bring the delivery forward. While both patients experienced a persistent increase in sympathetic tone and ventricular ectopic activity, no life-threatening arrhythmias were documented. During pregnancy, patients with hypertrophic cardiomyopathy develop progressive neuroautonomic imbalance, prompting an increase in non-sustained ventricular arrhythmia. This enhanced arrhythmia burden warrants close follow-up and rhythm assessment during the third trimester, especially in women who have heart failure symptoms before pregnancy. Implantable cardioverter defibrillators provide a continuous analysis of heart rate variability and arrhythmia burden that supports therapeutic decision-making during follow-up.

Impact of hypertension on global cardiovascular risk stratification: analysis of a large cohort of outpatient population in Italy

BACKGROUND

Control of hypertension remains a major unmet need, worldwide.

HYPOTHESIS

To test whether the presence of hypertension may improve global cardiovascular (CV) risk stratification and achievement of therapeutic targets for CV risk factors in adult outpatients in Italy.

METHODS

Physicians were asked to submit data covering the first 10 consecutive adult outpatients. All data were centrally analyzed for global CV risk assessment and rates of control of major CV risk factors, mostly blood pressure (BP) levels, in different high-risk subgroups of hypertensive patients.

RESULTS

Overall, 1078 physicians collected data of 9864 outpatients (46.7% females, age 66.1 ± 10.3 years) with valuable data on BP levels, among which 7147 (72.5%) had a diagnosis of hypertension and 2717 (27.5%) were normotensive subjects. Hypertensive patients were older and had a higher prevalence of major risk factors, including smoking, obesity, dyslipidemia, and family history of cardiovascular disease, as well as comorbidities, than did normotensive subjects (P < 0.001 for all comparisons). Despite worse control of BP (66.9% vs 36.2%, P < 0.001), high-density lipoprotein cholesterol (40.5% vs 37.4%, P < 0.005), triglycerides (72.1% vs 67.8%, P < 0.001), and fasting plasma glucose (71.2% vs 67.0%, P < 0.005), hypertension was associated with larger availability and frequency of diagnostic examinations and greater use of antihypertensive, glucose-lowering, and lipid-lowering drugs, as well as antiplatelet agents, compared with normotension (P < 0.001).

CONCLUSIONS

Presence of hypertension significantly improved clinical data collection and CV risk stratification. Such an approach, however, was not paralleled by better control of major CV risk factors.

Clinical management of patients with hypertension and high cardiovascular risk in specialised centers and in general practice. Analysis from an Italian Survey Questionnaire

BACKGROUND AND AIM

Hypertension control remains poorly achieved worldwide, despite the use of modern diagnostic tools and advanced therapeutic strategies. We aimed to evaluate the preferences expressed by either specialised physicians (SPs) or general practitioners (GPs) for the clinical management of hypertension and high cardiovascular risk in Italy.

METHODS AND RESULTS

A predefined questionnaire was anonymously administered to a large community sample of physicians, stratified according to clinical expertise. From a total of 64 questions, 557 physicians (478 male, mean age 54.2 ± 7.1 years, average age of medical activity 28.0 ± 8.1 years), including 261 (46.9%) SPs and 296 (53.1%) GPs, provided 9564 answers to the survey questionnaire. Involved clinicians spent the majority of their time and practice for hypertension management and control. SPs aimed to achieve the recommended BP targets (<140/90 mmHg), whereas GPs tended to achieve more rigorous BP goals (<130/80 mmHg); nonetheless, they both reported a very high rate of BP control (about 70%). Concomitant presence of diabetes, organ damage, as well as comorbidities, was reported to be relatively frequent (26-50%), mostly by SPs. ESH/ESC 2007 risk score stratification was preferred by SPs compared to GPs, who favored a comprehensive clinical evaluation. ACE inhibitors or ARBs were considered the best pharmacological option to start antihypertensive treatment, thus adding diuretics or calcium-channel blockers, if needed.

CONCLUSIONS

This predefined analysis of a survey questionnaire showed relatively different opinions with respect to recommended BP targets and distributions of cardiovascular risk profile, and similar diagnostic and therapeutic choices between GPs and SPs.

RyR2 Common Gene Variant G1886S and the Risk of Ventricular Arrhythmias in ICD Patients with Heart Failure

BACKGROUND

Cardiac ryanodine receptor 2 (RyR2) is critical to the electrical homeostasis of cardiomyocytes. Its gene variant rs3766871 entails channel destabilization and enhanced intracellular Ca(2+) oscillation, thus promoting cardiac arrhythmias. We investigated whether the RyR2 rs3766871 variant is associated with aborted sudden cardiac death or ICD therapy for ventricular tachycardia (VT)/fibrillation (VF) in heart failure (HF) patients implanted with a cardioverter defibrillator (ICD).

METHODS AND RESULTS

A total of 183 HF patients with primary or secondary prevention ICD were divided in 2 groups. A VT/VF group was composed of secondary prevention patients and primary prevention patients with appropriate ICD intervention for VT/VF. An ICD control group was composed of primary prevention patients free from any appropriate ICD intervention after 43 ± 25 months follow-up. Study subjects were genotyped with respect to the rs3766871 RyR2 gene variant. Hazard ratios (HRs) were derived from Cox proportional-hazards regression analysis. In all, 56 patients constituted the VT/VF group and 127 patients the ICD control group. Male sex (HR: 3.02; 95% CI: 0.99-9.18; P = 0.05), atrial fibrillation (AF; HR: 2.33; 95% CI: 0.89-6.10; P = 0.08), and underuse of β-blockers (HR: 2.08; 95% CI: 0.84-5.15; P = 0.11) were associated with the VT/VF phenotype. Prevalence of the rs3766871 minor allele was 2.8% in ICD control patients and 8.0% in the VT/VF group (P = 0.02). After adjustment for age, sex, AF, and use of β-blockers, the rs3766871 minor allele was associated with increased risk of VT/VF (HR: 3.49; 95% CI: 1.14-10.62; P = 0.02).

CONCLUSIONS

Our study identifies a significant role of RyR2 rs3766871 minor allele for increased susceptibility to VT/VF in a population of ICD patients with HF.

A Novel Electrocardiographic T-Wave Measurement (Tp-Te Interval) as a Predictor of Heart Abnormalities in Hypertension: A New Opportunity for First-Line Electrocardiographic Evaluation

The aim of the study was to evaluate the role of conventional and new markers of early cardiac organ damage (OD) on 12-lead electrocardiography (ECG) in 25 outpatients with newly diagnosed untreated essential hypertension compared with 15 normotensive, otherwise healthy individuals. Each participant underwent ECG, echocardiographic, and blood pressure (BP) measurements. Conventional and new ECG indexes for cardiac OD (Tp-Te interval, ventricular activation time, and P-wave analysis) were also measured. Clinic and 24-hour ambulatory BP levels as well as left ventricular mass indexes were significantly higher in hypertensive than in normotensive patients. No significant differences were found between the two groups for ECG and echocardiographic markers of OD. Only Tp-Te interval was higher in hypertensive than in normotensive individuals (3.06 mm vs 2.24 mm; P<.0001), even after adjustment for anthropometric and clinical parameters. Preliminary results of this study demonstrated prolonged Tp-Te interval in newly diagnosed, untreated hypertensive outpatients compared with normotensive individuals.

[The progression from hypertension to congestive heart failure]

Arterial hypertension still represents one of the major modifiable risk factors for cardiovascular and renal disease. Solid evidences are available demonstrating the large and significant benefits deriving from blood pressure lowering therapies in terms of reduced incidence of major cardiovascular events, including myocardial infarction, ischemic stroke and cardiovascular death. It should be also noted, however, that hypertensive patients are at increased risk of developing congestive heart failure, being this risk substantially independent by the concomitant presence of left ventricular hypertrophy or dysfunction. Indeed, it has been demonstrated that blood pressure reduction and control significantly reduce the risk of developing congestive heart failure. In particular, several recent meta-analyses have demonstrated that the use of diuretics and renin-angiotensin system blockers is superior to calcium-antagonists and beta-blockers in terms of prevention of new-onset heart failure. The present paper overviews the main pathophysiological aspects of the progression from arterial hypertension to congestive heart failure and the potential therapeutic interventions able to reduce or prevent this progression.

Angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers and diabetes: a meta-analysis of placebo-controlled clinical trials

BACKGROUND

To determine whether the administration of angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) on top of standard cardiovascular (CV) therapies may reduce the incidence of new onset diabetes (NOD) in placebo-controlled clinical trials. The effects of these drugs on CV and non-CV mortality were also tested.

METHODS

We performed a meta-analysis of all randomized clinical trials (11 trials, n = 84,363 patients, aged 64.2 ± 5.86 years), published until 14 March 2010, in which ACE inhibitors or ARBs were compared with placebo and NOD incidence, CV, and non-CV mortality were reported.

RESULTS

Over an average follow-up of 4.0 ± 1.0 years, there were 1,284/15,142 (8.5%) cases of NOD in active-treated and 1,411/15,130 (9.3%) cases in placebo-treated patients in the ACE inhibitor trials, and 2,330/18,756 (12.4%) cases in active-treated and 2,669/18,800 (14.2%) cases in placebo-treated patients in the ARB trials. Overall, active therapy reduced NOD compared to placebo (odds ratio (OR) 95%, confidence interval (CI): 0.8 (0.8-0.9); P < 0.01). Both ACE inhibitors (OR 95%, CI: 0.8 (0.7-1.0); P = 0.07) and ARBs (OR 95%, CI: 0.8 (0.8-0.9); P < 0.01) reduced NOD as compared to placebo. Active treatment reduced CV mortality (OR 95%, CI: 0.9 (0.8-1.0); P < 0.01) and had a favorable impact on non-CV mortality (OR 95%, CI: 0.7 (0.9-1.0); P = 0.2) as compared to placebo.

CONCLUSIONS

Our findings demonstrated that ACE inhibitors or ARBs should be preferred in patients with clinical conditions that may increase risk of NOD, since these drugs reduced NOD incidence. In addition, these drugs have favorable effects on CV and non-CV mortality in high CV risk patients.