Usefulness of inducible ventricular tachycardia to predict long-term adverse outcomes in arrhythmogenic right ventricular cardiomyopathy

The role of the electrophysiologic (EP) study for risk stratification in patients with arrhythmogenic right ventricular cardiomyopathy is controversial. We investigated the role of inducible sustained monomorphic ventricular tachycardia (SMVT) for the prediction of an adverse outcome (AO), defined as the occurrence of cardiac death, heart transplantation, sudden cardiac death, ventricular fibrillation, ventricular tachycardia with hemodynamic compromise or syncope. Of 62 patients who fulfilled the 2010 Arrhythmogenic Right Ventricular Cardiomyopathy Task Force criteria and underwent an EP study, 30 (48%) experienced an adverse outcome during a median follow-up of 9.8 years. SMVT was inducible in 34 patients (55%), 22 (65%) of whom had an adverse outcome. In contrast, in 28 patients without inducible SMVT, 8 (29%) had an adverse outcome. Kaplan-Meier analysis showed an event-free survival benefit for patients without inducible SMVT (log-rank p = 0.008) with a cumulative survival free of an adverse outcome of 72% (95% confidence interval [CI] 56% to 92%) in the group without inducible SMVT compared to 26% (95% CI 14% to 50%) in the other group after 10 years. The inducibility of SMVT during the EP study (hazard ratio [HR] 2.99, 95% CI 1.23 to 7.27), nonadherence (HR 2.74, 95% CI 1.3 to 5.77), and heart failure New York Heart Association functional class II and III (HR 2.25, 95% CI 1.04 to 4.87) were associated with an adverse outcome on univariate Cox regression analysis. The inducibility of SMVT (HR 2.52, 95% CI 1.03 to 6.16, p = 0.043) and nonadherence (HR 2.34, 95% CI 1.1 to 4.99, p = 0.028) remained as significant predictors on multivariate analysis. This long-term observational data suggest that SMVT inducibility during EP study might predict an adverse outcome in patients with arrhythmogenic right ventricular cardiomyopathy, advocating a role for EP study in risk stratification.

Interdisciplinary Cardiovascular and Neurologic Outpatient Rehabilitation in Patients Surviving Transient Ischemic Attack or Stroke With Minor or No Residual Deficits

Objective To evaluate the feasibility and effectiveness of a comprehensive outpatient rehabilitation program combining secondary prevention and neurorehabilitation to improve vascular risk factors, neurologic functions, and health-related quality of life (HRQOL) in patients surviving a transient ischemic attack (TIA) or stroke with minor or no residual deficits. Design Prospective interventional single-center cohort study. Setting University hospital. Participants Consecutive consenting patients having sustained a TIA or stroke with 1 or more vascular risk factors (N=105) were included. Interventions Three-month hospital-based secondary prevention and neurorehabilitation outpatient program with therapeutic and educational sessions twice a week. Patients were evaluated at entry and program end. Main Outcome Measures Impact on vascular risk factors, neurological outcome, and HRQOL. Results A total of 105 patients entered the program and 95 patients completed it. Exercise capacity (P<.000), smoking status (P=.001), systolic (P=.001) and diastolic (P=.008) blood pressure, body mass index (P=.005), low-density lipoprotein cholesterol (P=.03), and triglycerides (P=.001) improved significantly. Furthermore, the 9-Hole-Peg-Test (P<.000), Six-minute Walking Test (P<.000), and One Leg Stand Test (P<.011) values as well as HRQOL improved significantly. The program could be easily integrated into an existing cardiovascular prevention and rehabilitation center and was feasible and highly accepted by patients. Conclusions Comprehensive combined cardiovascular and neurologic outpatient rehabilitation is feasible and effective to improve vascular risk factors, neurologic functions, and HRQOL in patients surviving TIA or stroke with minor or no residual deficits.

The HeartQoL: Part II. Validation of a new core health-related quality of life questionnaire for patients with ischemic heart disease

Background: Evaluation of health-related quality of life (HRQL) is important in improving the quality of patient care. The aim of this study was to determine the psychometric properties of the HeartQoL in patients with ischemic heart disease (IHD), specifically angina, myocardial infarction (MI), or ischemic heart failure. Methods: Data for the interim validation of the HeartQoL questionnaire were collected in (a) a cross-sectional survey and (b) a prospective substudy of patients undergoing either a percutaneous coronary intervention (PCI) or referred to cardiac rehabilitation (CR) and were then analyzed to determine the reliability, validity, and responsiveness of the HeartQoL questionnaire. Results: We enrolled 6384 patients (angina, n = 2111, 33.1%; MI, n = 2351, 36.8%; heart failure, n = 1922, 30.1%) across 22 countries speaking 15 languages in the cross-sectional study and 730 patients with IHD in the prospective substudy. The HeartQoL questionnaire comprises 14-items with physical and emotional subscales and a global score (range 0–3 (poor to better HRQL). Cronbach’s α was consistently ≥0.80; convergent validity correlations between similar HeartQoL and SF-36 subscales were significant (r ≥ 0.60, p < 0.001); discriminative validity was confirmed with predictor variables: health transition, anxiety, depression, and functional status. HeartQoL score changes following either PCI or CR were significant (p < 0.001) with effect sizes ranging from 0.37–0.64. Conclusion: The HeartQoL questionnaire is reliable, valid, and responsive to change allowing clinicians and researchers to (a) assess baseline HRQL, (b) make between-diagnosis comparisons of HRQL, and (c) evaluate change in HRQL in patients with angina, MI, or heart failure with a single IHD-specific HRQL instrument.

The HeartQoL: Part I. Development of a new core health-related quality of life questionnaire for patients with ischemic heart disease

Background: Evaluation of health-related quality of life (HRQL) is important in improving the quality of patient care. Methods: The HeartQoL Project, with cross-sectional and longitudinal phases, was designed to develop a core ischemic heart disease (IHD) specific HRQL questionnaire, to be called the HeartQoL, for patients with angina, myocardial infarction (MI), or ischemic heart failure. Patients completed a battery of questionnaires and Mokken scaling analysis was used to identify items in the HeartQoL questionnaire. Results: We enrolled 6384 patients (angina, n = 2111, 33.1%; MI, n = 2351, 36.8%; heart failure, n = 1922, 30.1%) across 22 countries and 15 languages. The HeartQoL questionnaire comprises 14-items with 10-item physical and 4-item emotional subscales which are scored from 0 (poor HRQL) to 3 (better HRQL) with a global score if needed. The mean baseline HeartQoL global score was 2.2 (±0.5) in the total group and was different (p < 0.001) by diagnosis (MI, 2.4 ± 0.5; angina, 2.2 ± 0.6; and heart failure, 2.1 ± 0.6). Conclusion: The HeartQoL questionnaire, with global and subscale scores, has the potential to allow clinicians and researchers to (a) assess baseline HRQL, (b) make between-diagnosis comparisons of HRQL, and (c) evaluate change in HRQL in patients with angina, MI, or heart failure with a single IHD-specific HRQL instrument.

NaV1.5 and interacting proteins in human arrhythmogenic cardiomyopathy

Evaluation of: Noorman M, Hakim S, Kessler E et al. Remodeling of the cardiac sodium channel, connexin43, and plakoglobin at the intercalated disk in patients with arrhythmogenic cardiomyopathy. Heart Rhythm 10(3), 412-419 (2013). Arrhythmogenic cardiomyopathy (AC) is a heart muscle disease characterized by a progressive replacement of the ventricular myocardium with adipose and fibrous tissue. This disease is often associated with mutations in genes encoding desmosomal proteins in the majority of patients. Based on results obtained from recent experimental models, a disturbed distribution of gap junction proteins and cardiac sodium channels may also be observed in AC phenotypes, secondary to desmosomal dysfunction. The study from Noorman et al. examined heart sections from patients diagnosed with AC and performed immunohistochemical analyses of N-cadherin, PKP2, PKG, Cx43 and the cardiac sodium channel NaV1.5. Altered expression/distribution of Cx43, PKG and NaV1.5 was found in most cases of patients with AC. The altered expression and/or distribution of NaV1.5 channels in AC hearts may play a mechanistic role in the arrhythmias leading to sudden cardiac death in AC patients. Thus, NaV1.5 should be considered as a supplemental element in the evaluation of risk stratification and management strategies. However, additional experiments are required to clearly understand the mechanisms leading to AC phenotypes.

Hierarchical accumulation of RyR post-translational modifications drives disease progression in dystrophic cardiomyopathy

AIMS:Duchenne muscular dystrophy (DMD) is a muscle disease with serious cardiac complications. Changes in Ca(2+) homeostasis and oxidative stress were recently associated with cardiac deterioration, but the cellular pathophysiological mechanisms remain elusive. We investigated whether the activity of ryanodine receptor (RyR) Ca(2+) release channels is affected, whether changes in function are cause or consequence and which post-translational modifications drive disease progression. METHODS AND RESULTS:Electrophysiological, imaging, and biochemical techniques were used to study RyRs in cardiomyocytes from mdx mice, an animal model of DMD. Young mdx mice show no changes in cardiac performance, but do so after ∼8 months. Nevertheless, myocytes from mdx pups exhibited exaggerated Ca(2+) responses to mechanical stress and 'hypersensitive' excitation-contraction coupling, hallmarks of increased RyR Ca(2+) sensitivity. Both were normalized by antioxidants, inhibitors of NAD(P)H oxidase and CaMKII, but not by NO synthases and PKA antagonists. Sarcoplasmic reticulum Ca(2+) load and leak were unchanged in young mdx mice. However, by the age of 4-5 months and in senescence, leak was increased and load was reduced, indicating disease progression. By this age, all pharmacological interventions listed above normalized Ca(2+) signals and corrected changes in ECC, Ca(2+) load, and leak. CONCLUSION:Our findings suggest that increased RyR Ca(2+) sensitivity precedes and presumably drives the progression of dystrophic cardiomyopathy, with oxidative stress initiating its development. RyR oxidation followed by phosphorylation, first by CaMKII and later by PKA, synergistically contributes to cardiac deterioration.

Botulinum toxin A and B raise blood flow and increase survival of critically ischemic skin flaps

BACKGROUND Botulinum toxin (BTX) A and B are commonly used for aesthetic indications and in neuromuscular disorders. New concepts seek to prove efficacy of BTX for critical tissue perfusion. Our aim was to evaluate BTX A and B in a mouse model of critical flap ischemia for preoperative and intraoperative application. METHODS BTX A and B were applied on the vascular pedicle of an axial pattern flap in mice preoperatively or intraoperatively. Blood flow, tissue oxygenation, tissue metabolism, flap necrosis rate, apoptosis assay, and RhoA and eNOS expression were endpoints. RESULTS Blood-flow measurements 1 d after the flap operation revealed a significant reduction to 53% in the control group, while flow was maintained or increased in all BTX groups (103%-129%). Over 5 d all BTX groups showed significant increase in blood flow to 166-187% (P < 0.01). Microdialysis revealed an increase of glucose and reduced lactate/pyruvate ratio and glycerol levels in the flap tissue of all BTX groups. This resulted in significantly improved tissue survival in all BTX groups compared with the control group (62% ± 10%; all P < 0.01): BTX A preconditioning (84% ± 5%), BTX A application intraoperatively (88% ± 4%), BTX B preconditioning (91% ± 4%), and intraoperative BTX B treatment (92% ± 5%). This was confirmed by TUNEL assay. Immunofluorescence demonstrated RhoA and eNOS expression in BTX groups. All BTX applications were similarly effective, despite pharmacologic dissimilarities and different timing. CONCLUSIONS In conclusion, we were able to show on a vascular, tissue, cell, and molecular level that BTX injection to the feeding arteries supports flap survival through ameliorated blood flow and oxygen delivery.

Prospective, multicenter, single-arm study of mechanical thrombectomy using Solitaire Flow Restoration in acute ischemic stroke

BACKGROUND AND PURPOSE Mechanical thrombectomy using stent retriever devices have been advocated to increase revascularization in intracranial vessel occlusion. We present the results of a large prospective study on the use of the Solitaire Flow Restoration in patients with acute ischemic stroke. METHODS Solitaire Flow Restoration Thrombectomy for Acute Revascularization was an international, multicenter, prospective, single-arm study of Solitaire Flow Restoration thrombectomy in patients with large vessel anterior circulation strokes treated within 8 hours of symptom onset. Strict criteria for site selection were applied. The primary end point was the revascularization rate (thrombolysis in cerebral infarction ≥2b) of the occluded vessel as determined by an independent core laboratory. The secondary end point was the rate of good functional outcome (defined as 90-day modified Rankin scale, 0-2). RESULTS A total of 202 patients were enrolled across 14 comprehensive stroke centers in Europe, Canada, and Australia. The median age was 72 years, 60% were female patients. The median National Institute of Health Stroke Scale was 17. Most proximal intracranial occlusion was the internal carotid artery in 18%, and the middle cerebral artery in 82%. Successful revascularization was achieved in 79.2% of patients. Device and procedure-related severe adverse events were found in 7.4%. Favorable neurological outcome was found in 57.9%. The mortality rate was 6.9%. Any intracranial hemorrhagic transformation was found in 18.8% of patients, 1.5% were symptomatic. CONCLUSIONS In this single-arm study, treatment with the Solitaire Flow Restoration device in intracranial anterior circulation occlusions results in high rates of revascularization, low risk of clinically relevant procedural complications, and good clinical outcomes in combination with low mortality at 90 days. CLINICAL TRIAL REGISTRATION URL http://www.clinicaltrials.gov. Unique identifier: NCT01327989.

Impact of Age and Baseline NIHSS Scores on Clinical Outcomes in the Mechanical Thrombectomy Using Solitaire FR in Acute Ischemic Stroke Study

BACKGROUND AND PURPOSE Age and stroke severity are inversely correlated with the odds of favorable outcome after ischemic stroke. A previously proposed score for Stroke Prognostication Using Age and NIHSS Stroke Scale (SPAN) indicated that SPAN-100-positive patients (ie, age + NIHSS score = 100 or more) do not benefit from IV-tPA. If this finding holds true for endovascular therapy, this score can impact patient selection for such interventions. This study investigated whether a score combining age and NIHSS score can improve patients' selection for endovascular stroke therapy. MATERIALS AND METHODS The SPAN index was calculated for patients in the prospective Solitaire FR Thrombectomy for Acute Revascularization study: an international single-arm multicenter cohort for anterior circulation stroke treatment by using the Solitaire FR. The proportion with favorable outcome (90-day mRS score ≤2) was compared between SPAN-100-positive versus-negative patients. RESULTS Of the 202 patients enrolled, 196 had baseline NIHSS scores. Fifteen (7.7%) patients were SPAN-100-positive. There was no difference in the rate of successful reperfusion (Thrombolysis In Cerebral Infarction 2b or 3) between SPAN-100-positive versus -negative groups (93.3% versus 82.8%, respectively; P = .3). Stroke SPAN-100-positive patients had a significantly lower proportion of favorable clinical outcomes (26.7% versus 60.8% in SPAN-100-negative, P = .01). In a multivariable analysis, SPAN-100-positive status was associated with lower odds of favorable outcome (OR, 0.3; 95% CI, 0.1-0.9; P = .04). A higher baseline Alberta Stroke Program Early CT Score and a short onset to revascularization time also predicted favorable outcome in the multivariable analysis. CONCLUSIONS A significantly lower proportion of patients with a positive SPAN-100 achieved favorable outcome in this cohort. SPAN-100 was an independent predictor of favorable outcome after adjusting for time to treatment and the extent of preintervention tissue damage according to the Alberta Stroke Program Early CT Score.

Reply to the editor

We appreciate the comments and concerns expressed by Arakawa and colleagues regarding our article, titled “Pulsatile control of rotary blood pumps: Does the modulation waveform matter?”1 Unfortunately, we have to disagree with Arakawa and colleagues. As is obvious from the title of our article, it investigates the effect of different waveforms on the heart–device interaction. In contrast to the authors' claim, this is the first article in the literature that uses basic waveforms (sine, triangle, saw tooth, and rectangular) with different phase shifts to examines their impact on left ventricular unloading. The previous publications2, 3 and 4 just varied the pump speed during systole and diastole, which was first reported by Bearnson and associates5 in 1996, and studied its effect on aortic pressure, coronary flow, and end-diastolic volume. We should mention that dp/dtmax is a load-sensitive parameter of contractility and not representative for the degree of unloading. Moreover, none of the aforementioned reports has studied mechanical unloading and in particular the stroke work of the left ventricle. Our method is unique because we do not just alternate between high and low speed but have accurate control of the waveform because of the direct drive system of Levitronix Technologies LLC (Waltham, Mass) and a custom-developed pump controller. Without referring, Arakawa and associates state “several previous studies have already reported the coronary flow diminishes as the left ventricular assist device support increases.” It should be noted that all the waveforms used in our study have 2000 rpm average value with 1000 rpm amplitude, which is not an excessive speed for the CentriMag rotary pump (Levitronix) to collapse the ventricle and diminish the coronary flow. We agree with Arakawa and coworkers that there is a need for a heart failure model to come to more relevant results with respect to clinical expectations. However, we have explored many existing models, including species and breeds that have a native proneness to cardiomyopathy, but all of them differ from the genetic presentation in humans. We certainly do not believe that the use of microembolization, in which the coronary circulation is impaired by the injection of microspheres, would form a good model from which to draw conclusions about coronary flow change under different loading conditions. A model would be needed in which either an infarct is created to mimic ischemic heart failure or the coronary circulation remains untouched to simulate, for instance, dilated cardiomyopathy. Furthermore, in discussion we clearly mention that “lack of heart failure is a major limitation of our study.” We also believe that unloading is not the only factor of the cardiac functional recovery, and an excessive unloading of the left ventricle might lead to cardiac tissue atrophy. Therefore, in our article we mention that control of the level of cardiac unloading by assist devices has been suggested as a mechanical tool to promote recovery, and more studies are required to find better strategies for the speed modulation of rotary pumps and to achieve an optimal heart load control to enhance myocardial recovery. Finally, there are many publications about pulsing rotary blood pumps and it was impossible to include them all. We preferred to reference some of the earlier basic works such as an original research by Bearnson and coworkers5 and another article published by our group,6 which is more relevant.

Effects of hypoxic-ischemic encephalopathy and whole-body hypothermia on neonatal auditory function: a pilot study.

We assessed the effects of hypoxic-ischemic encephalopathy (HIE) and whole-body hypothermia therapy on auditory brain stem evoked responses (ABRs) and distortion product otoacoustic emissions (DPOAEs). We performed serial assessments of ABRs and DPOAEs in newborns with moderate or severe HIE, randomized to hypothermia ( N = 4) or usual care ( N = 5). Participants were five boys and four girls with mean gestational age (standard deviation) of 38.9 (1.8) weeks. During the first week of life, peripheral auditory function, as measured by the DPOAEs, was disrupted in all nine subjects. ABRs were delayed but central transmission was intact, suggesting a peripheral rather than a central neural insult. By 3 weeks of age, peripheral auditory function normalized. Hypothermia temporarily prolonged the ABR, more so for waves generated higher in the brain stem but the effects reversed quickly on rewarming. Neonatal audiometric testing is feasible, noninvasive, and capable of enhancing our understanding of the effects of HIE and hypothermia on auditory function.

Outcomes of safety and effectiveness in a multicenter randomized, controlled trial of whole-body hypothermia for neonatal hypoxic-ischemic encephalopathy.

BACKGROUND: Whole-body hypothermia reduced the frequency of death or moderate/severe disabilities in neonates with hypoxic-ischemic encephalopathy in a randomized, controlled multicenter trial. OBJECTIVE: Our goal was to evaluate outcomes of safety and effectiveness of hypothermia in infants up to 18 to 22 months of age. DESIGN/METHODS: A priori outcomes were evaluated between hypothermia (n = 102) and control (n = 106) groups. RESULTS: Encephalopathy attributable to causes other than hypoxia-ischemia at birth was not noted. Inotropic support (hypothermia, 59% of infants; control, 56% of infants) was similar during the 72-hour study intervention period in both groups. Need for blood transfusions (hypothermia, 24%; control, 24%), platelet transfusions (hypothermia, 20%; control, 12%), and volume expanders (hypothermia, 54%; control, 49%) was similar in the 2 groups. Among infants with persistent pulmonary hypertension (hypothermia, 25%; control, 22%), nitric-oxide use (hypothermia, 68%; control, 57%) and placement on extracorporeal membrane oxygenation (hypothermia, 4%; control, 9%) was similar between the 2 groups. Non-central nervous system organ dysfunctions occurred with similar frequency in the hypothermia (74%) and control (73%) groups. Rehospitalization occurred among 27% of the infants in the hypothermia group and 42% of infants in the control group. At 18 months, the hypothermia group had 24 deaths, 19 severe disabilities, and 2 moderate disabilities, whereas the control group had 38 deaths, 25 severe disabilities, and 1 moderate disability. Growth parameters were similar between survivors. No adverse outcomes were noted among infants receiving hypothermia with transient reduction of temperature below a target of 33.5 degrees C at initiation of cooling. There was a trend in reduction of frequency of all outcomes in the hypothermia group compared with the control group in both moderate and severe encephalopathy categories. CONCLUSIONS: Although not powered to test these secondary outcomes, whole-body hypothermia in infants with encephalopathy was safe and was associated with a consistent trend for decreasing frequency of each of the components of disability.

ANKRD1, the gene encoding cardiac ankyrin repeat protein, is a novel dilated cardiomyopathy gene.

OBJECTIVES: We evaluated ankyrin repeat domain 1 (ANKRD1), the gene encoding cardiac ankyrin repeat protein (CARP), as a novel candidate gene for dilated cardiomyopathy (DCM) through mutation analysis of a cohort of familial or idiopathic DCM patients, based on the hypothesis that inherited dysfunction of mechanical stretch-based signaling is present in a subset of DCM patients. BACKGROUND: CARP, a transcription coinhibitor, is a member of the titin-N2A mechanosensory complex and translocates to the nucleus in response to stretch. It is up-regulated in cardiac failure and hypertrophy and represses expression of sarcomeric proteins. Its overexpression results in contractile dysfunction. METHODS: In all, 208 DCM patients were screened for mutations/variants in the coding region of ANKRD1 using polymerase chain reaction, denaturing high-performance liquid chromatography, and direct deoxyribonucleic acid sequencing. In vitro functional analyses of the mutation were performed using yeast 2-hybrid assays and investigating the effect on stretch-mediated gene expression in myoblastoid cell lines using quantitative real-time reverse transcription-polymerase chain reaction. RESULTS: Three missense heterozygous ANKRD1 mutations (P105S, V107L, and M184I) were identified in 4 DCM patients. The M184I mutation results in loss of CARP binding with Talin 1 and FHL2, and the P105S mutation in loss of Talin 1 binding. Intracellular localization of mutant CARP proteins is not altered. The mutations result in differential stretch-induced gene expression compared with wild-type CARP. CONCLUSIONS: ANKRD1 is a novel DCM gene, with mutations present in 1.9% of DCM patients. The ANKRD1 mutations may cause DCM as a result of disruption of the normal cardiac stretch-based signaling.