Retinal transduction profiles by high-capacity viral vectors

Retinal gene therapy with adeno-associated viral (AAV) vectors is safe and effective in humans. However, the limited cargo capacity of AAV prevents their use for therapy of those inherited retinopathies (IRs) due to mutations in large (>5kb) genes. Viral vectors derived from Adenovirus (Ad), Lentivirus (LV) and Herpesvirus (HV) can package large DNA sequences but do not target efficiently retinal photoreceptors (PRs) where the majority of genes responsible for IRs are expressed.

Here, we have evaluated the mouse retinal transduction profiles of vectors derived from 16 different Ad serotypes, 7 LV pseudotypes, and from a bovine HV. Most of the vectors tested transduced efficiently the retinal pigment epithelium (RPE). We found that LV-GP64 tends to transduce more PRs than the canonical LV-VSVG albeit this was restricted to a narrow region. We observed more extensive PR transduction with HdAd1, 2 and 5/F35++ than with LV, although none of them outperformed the canonical HdAd5 or matched the extension of PR transduction achieved with AAV2/8.

Personality traits, cardiac risk factors, and their association with presence and severity of coronary artery plaque in people with no history of cardiovascular disease

BACKGROUND

Coronary artery disease (CAD) is a multifactorial complex disease. The aim of the present study is to verify whether the personality traits in CAD are associated with coronary artery plaque (CAP) presence and severity in people with no history of cardiovascular disease.

DESIGN

A cross-sectional monocenter study.

METHODS

Seventy five individuals with no history of CAD underwent 64-slice computed tomography coronary angiography (CTCA) and were screened for traditional cardiac risk factors and for hostility, anger, and type D personality traits.

RESULTS

In total, 48 patients (64%) had evidence of CAP, with mild (31%), moderate (33%), and severe (35%) coronary stenosis. Male sex, hypertension, being overweight, and number of cardiovascular risk factors increased the likelihood of CAP presence. Findings showed a significant difference between CAP presence vs. CAP absence for anger (26 vs. 30%, χ2 = 6.82) and type D personality (23 vs. 35%; χ2 = 8.23, P = 0.03), but not hostility (P > 0.05). Anger personality, and the type D subscale social inhibition, but not negative affectivity, were associated with an increased prevalence and severity of CAP. Univariate analysis confirms anger (odds ratio, OR = 1.38, 95% confidence interval, CI = 1.12-2.31), social inhibition (OR = 2.01, 95% CI = 1.81-2.93), 'negative affectivity by social inhibition' (OR = 1.24, 95% CI = 1.12-2.14), and type D personality (OR = 1.9, 95% CI = 1.11-2.03) as predictors of CAP presence. Moreover, multivariate analysis suggests social inhibition as also a unique CAP predictor (OR = 2.14, 95% CI = 1.89-2.96) after adjustment for having cardiac risk factors as a covariate.

CONCLUSION

The present data confirm the core role of traditional risk factors and suggest the primacy of social inhibition and anger personality traits in association with CAP presence and severity.

Long-term effectiveness of the combined minute ventilation and patient activity sensors as predictor of heart failure events in patients treated with cardiac resynchronization therapy: Results of the Clinical Evaluation of the Physiological Diagnosis Function in the PARADYM CRT device Trial (CLEPSYDRA) study

AIMS

Monitoring early signs of clinical deterioration could allow physicians to adjust medical treatment for patients at risk of acute heart failure decompensation. To date, several strategies using different surrogate measures of clinical status emerged, but none has yet been proven to predict clinical events. We hypothesized that the Physiological Diagnostic feature, which combines data from minute ventilation and physical activity sensors, predicts heart failure events in patients implanted with cardiac resynchronization therapy with defibrillation (CRT-D) devices.

METHODS AND RESULTS

The Clinical Evaluation of the Physiological Diagnostic feature in the PARADYM CRT device (CLEPSYDRA) trial is a multicentre, prospective, non-randomized, double-blind study comprising 521 CRT-D patients with heart failure [67.4 ± 10.1 years (mean ± SD), 82% male, New York Heart Association class III/IV 85.0%/6.7%, QRS 155.3 ± 26.6 ms, left ventricular ejection fraction 25.7 ± 7.7%]. The objective of the study was the sensitivity and false positive rate of the Physiological Diagnostic algorithm to predict heart failure events within the following month. After a mean follow-up of 17.0 ± 8.7 months, 130 (25.6%) patients experienced a heart failure event. The sensitivity of the algorithm to predict an event was 34% and the false positive rate was 2.4 per patient-year.

CONCLUSION

Thirty-four per cent of heart failure events occurring within a month were predicted by the Physiological Diagnostic algorithm, and 2.4 alerts per patient per year were not followed by an heart failure event within the subsequent month.

Absolute survival after cardiac resynchronization therapy according to baseline QRS duration: a multinational 10-year experience: data from the Multicenter International CRT Study

BACKGROUND

In the major trials of cardiac resynchronization therapy (CRT), the survival benefit of the therapy, relative to control subjects, increases with QRS duration. In the non-CRT heart failure population, however, a wide QRS duration is associated with a shorter survival. Relative survival benefit from a therapy, however, is not synonymous with a longer absolute survival. We sought to determine whether baseline QRS duration relates to the absolute survival after CRT.

METHODS AND RESULTS

In this prospective, longitudinal, observational study, 3,319 consecutive patients undergoing CRT (QRS 120-149 ms 26%, QRS 150-199 ms 58%, and QRS ≥200 ms 16%) were assessed in relation to mortality over 10 years. Overall mortality rates (per 100 patient-years) were 9.2%, 9.3%, and 13.3% in the 3 groups, respectively (all P < .001). Cardiac mortality rates were 6.2, 6.0, and 9.9 per 100 patient-years, respectively (all P < .001). Compared with the QRS 120-149 ms group, cardiac mortality was highest in the QRS ≥200 ms group (hazard ratio [HR] 1.72 [95% CI 1.35-2.19], P < .001), independent of age, gender, New York Heart Association class, presence of atrial fibrillation, heart failure etiology, and left ventricular ejection fraction. Median survival after CRT was longest in patients with a width of QRS 120-149 ms and shortest in patients with a QRS ≥200 ms (P < .001). In multivariable analyses, a QRS ≥200 ms emerged as a powerful independent predictor of both overall (HR 1.44 [95% CI 1.07-1.94], P = .017) and cardiac mortality (HR 1.59 [95% CI 1.14-2.24], P = .007).

CONCLUSIONS

At long-term follow-up, absolute overall and cardiac survival after CRT is similar in patients with a preimplant QRS duration of 120 to 149 ms and 150 to 199 ms but markedly shorter in patients with a QRS ≥200 ms.

Mechanical dyssynchrony precedes QRS widening in ATP-sensitive K⁺ channel-deficient dilated cardiomyopathy

Background

Contractile discordance exacerbates cardiac dysfunction, aggravating heart failure outcome. Dissecting the genesis of mechanical dyssynchrony would enable an early diagnosis before advanced disease.

Methods and Results

High‐resolution speckle‐tracking echocardiography was applied in a knockout murine surrogate of adult‐onset human cardiomyopathy caused by mutations in cardioprotective ATP‐sensitive K⁺ (K_ATP) channels. Preceding the established criteria of cardiac dyssynchrony, multiparametric speckle‐based strain resolved nascent erosion of dysfunctional regions within cardiomyopathic ventricles of the K_ATP channel–null mutant exposed to hemodynamic stress. Not observed in wild‐type counterparts, intraventricular disparity in wall motion, validated by the degree, direction, and delay of myocardial speckle patterns, unmasked the disease substrate from asymptomatic to overt heart failure. Mechanical dyssynchrony preceded widening of the QRS complex and exercise intolerance and progressed into global myocardial discoordination and decompensated cardiac pump function, precipitating a low output syndrome.

Conclusions

The present study, with the use of high‐resolution imaging, prospectively resolved the origin and extent of intraventricular motion disparity in a K_ATP channel–knockout model of dilated cardiomyopathy. Mechanical dyssynchrony established as an early marker of cardiomyopathic disease offers novel insight into the pathodynamics of dyssynchronous heart failure.

Interplay of electrical wavefronts as determinant of the response to cardiac resynchronization therapy in dyssynchronous canine hearts

BACKGROUND

The relative contribution of electromechanical synchronization and ventricular filling to the optimal hemodynamic effect in cardiac resynchronization therapy (CRT) during adjustment of stimulation-timings is incompletely understood. We investigated whether optimal hemodynamic effect in CRT requires collision of pacing-induced and intrinsic activation waves and optimal filling of the left ventricle (LV).

METHODS AND RESULTS

CRT was performed in dogs with chronic left bundle-branch block (n=8) or atrioventricular (AV) block (n=6) through atrial (A), right ventricular (RV) apex, and LV-basolateral pacing. A 100 randomized combinations of A-LV/A-RV intervals were tested. Total activation time (TAT) was calculated from >100 contact mapping electrodes. Mechanical interventricular dyssynchrony was determined as the time delay between upslopes of LV and RV pressure curves. Settings providing an increase in LVdP/dtmax (maximal rate of rise of left ventricular pressure) of ≥90% of the maximum LVdP/dtmax value were defined as optimal (CRTopt). Filling was assessed by changes in LV end-diastolic volume (EDV; conductance catheter technique). In all hearts, CRTopt was observed during multiple settings, providing an average LVdP/dtmax increase of ≈15%. In AV-block hearts, CRTopt exclusively depended on interventricular-interval and not on AV-interval. In left bundle-branch block hearts, CRTopt occurred at A-LV intervals that allowed fusion of LV-pacing-derived activation with right bundle-derived activation. In all animals, CRTopt occurred at settings resulting in the largest decrease in TAT and mechanical interventricular dyssynchrony, whereas LV EDV hardly changed.

CONCLUSIONS

In left bundle-branch block and AV-block hearts, optimal hemodynamic effect of CRT depends on optimal interplay between pacing-induced and intrinsic activation waves and the corresponding mechanical resynchronization rather than filling.

ELECTRa (European Lead Extraction ConTRolled) Registry--shedding light on transvenous lead extraction real-world practice in Europe

With the growing recognition of the clinical need and wider indications for cardiovascular implantable electronic devices (CIED), the number of implant procedures has increased considerably. Consequently, the rate of complications related to these devices has also increased. Transvenous lead extraction (TLE) is the gold standard in the treatment of CIED-related infective complications and is often required in the management of lead malfunction. An increasing number of centers currently perform TLE procedures. The ELECTRa (European Lead Extraction ConTRolled) Registry is the first large prospective multicenter registry of consecutive patients undergoing TLE in Europe, conducted by the European Heart Rhythm Association (EHRA) and managed by the European Society of Cardiology (ESC) EURObservational Research Department. The primary objective of the registry is to evaluate the acute and long-term safety of TLE; the secondary objective is to describe the characteristics of the patients, the leads, the indications for TLE, and the tools and techniques currently used for TLE. About 100 centers will be enrolled on a voluntary basis from European countries; they are anonymous and stratified on the basis of their volume of activity into high-volume centers (>30 patients/year) and low-volume centers: (≤30 patients/year). Each participating center will have to enroll and follow up for 1 year consecutively assessed patients undergoing TLE from November 2012 to January 2014. The target is to achieve a sample size of at least 3,500 patients for statistical analysis. Data will be collected using a Web-based system and will be audited at randomly selected centers. The official start was on 6 November. Eighty-nine centers have joined so far, 65 centers are currently active, those who have already obtained the approval of their own ethics committee, and 1,099 patients were enrolled at the end of June 2013. The independence of the registry, the consecutiveness of the patient enrolment, and the monitoring of the study are characteristics of this registry that will contribute to the scientific validity of the objectives to be achieved.