Clinical Features and Natural History of Preadolescent Nonsyndromic Hypertrophic Cardiomyopathy

BACKGROUND

Up to one-half of childhood sarcomeric hypertrophic cardiomyopathy (HCM) presents before the age of 12 years, but this patient group has not been systematically characterized.

OBJECTIVES

The aim of this study was to describe the clinical presentation and natural history of patients presenting with nonsyndromic HCM before the age of 12 years.

METHODS

Data from the International Paediatric Hypertrophic Cardiomyopathy Consortium on 639 children diagnosed with HCM younger than 12 years were collected and compared with those from 568 children diagnosed between 12 and 16 years.

RESULTS

At baseline, 339 patients (53.6%) had family histories of HCM, 132 (20.9%) had heart failure symptoms, and 250 (39.2%) were prescribed cardiac medications. The median maximal left ventricular wall thickness z-score was 8.7 (IQR: 5.3-14.4), and 145 patients (27.2%) had left ventricular outflow tract obstruction. Over a median follow-up period of 5.6 years (IQR: 2.3-10.0 years), 42 patients (6.6%) died, 21 (3.3%) underwent cardiac transplantation, and 69 (10.8%) had life-threatening arrhythmic events. Compared with those presenting after 12 years, a higher proportion of younger patients underwent myectomy (10.5% vs 7.2%; P = 0.045), but fewer received primary prevention implantable cardioverter-defibrillators (18.9% vs 30.1%; P = 0.041). The incidence of mortality or life-threatening arrhythmic events did not differ, but events occurred at a younger age.

CONCLUSIONS

Early-onset childhood HCM is associated with a comparable symptom burden and cardiac phenotype as in patients presenting later in childhood. Long-term outcomes including mortality did not differ by age of presentation, but patients presenting at younger than 12 years experienced adverse events at younger ages.

P390 ADIPOSITY AND VASCULAR AGEING: WHICH PARAMETER BETTER CORRELATES?

The increase in stiffness of large arteries is one of the mechanisms that could play a role in the association between obesity and increased risk of cardiovascular (CV) events. Carotid–femoral pulse wave velocity (cfPWV), known as an independent CV risk factor, represents a validated measure of large arteries stiffness and a good proxy of arterial ageing. We aimed at evaluating which body composition parameters better correlated with cfPWV and whether this correlation differed between men and women. cfPWV was measured in all subjects with Sphigmocor by sequentially recording electrocardiogram–gated carotid and femoral artery waveforms; body composition was measured by bioimpedance analysis and waist circumference (W). Furthermore, each subject was characterized by sex, age, height, weight, body mass index (BMI), brachial blood pressure (BP) and heart rate. A linear correlation was used to define the relationship between cfPWV and parameters. Univariate and multivariate analysis were performed in male and female subgroups separately to select the main determinants of arterial stiffness, considering the following parameters: age, mean BP (mBP), BMI, W, fat mass (FM) and skeletal muscle mass (SMM). We enrolled 69 subjects (37 men, 32 women) with average age 34.5 years (min 19–max 76). cfPWV was significantly correlated with age (r = 0.65, p<.0001), and mBP (r = 0.38, p<.01). Among the body composition parameters, W, BMI and FM percentage were significantly correlated with cfPWV (respectively: r = 0.48, r = 0.42, r = 0.41; p<.0001). Multivariable regression analysis in men revealed that age and mBP were significant determinants of cfPWV (respectively: b = 0.042, p = 0.002; b = 0.051, p = 0.004). Conversely, multivariate analysis in women showed that age, FM and SMM are retained as main determinants of increased cfPWV (respectively: b = 0.079; p < 0.0001; b = 0.217, p = 0.012; b = 0.125, p = 0.011). Irrespectively of gender, age is the main determinant of arterial stiffness. Our results demonstrated that the relationship between adiposity and arterial stiffness is verified only in female subjects. This suggests that this relationship is influenced by complex and not fully known mechanisms. Moreover, technical factors (algorithm and indirect methods to assess body composition) contribute to uncertainty regarding which parameter exploring adiposity is more accurate in stratifying CV risk.

The present study recalls attention on possible gender–specific determinants of arterial ageing.

Relationship Between Maximal Left Ventricular Wall Thickness and Sudden Cardiac Death in Childhood Onset Hypertrophic Cardiomyopathy

BACKGROUND

Maximal left ventricular wall thickness (MLVWT) is a risk factor for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). In adults, the severity of left ventricular hypertrophy has a nonlinear relationship with SCD, but it is not known whether the same complex relationship is seen in childhood. The aim of this study was to describe the relationship between left ventricular hypertrophy and SCD risk in a large international pediatric HCM cohort.

METHODS

The study cohort comprised 1075 children (mean age, 10.2 years [±4.4]) diagnosed with HCM (1-16 years) from the International Paediatric Hypertrophic Cardiomyopathy Consortium. Anonymized, noninvasive clinical data were collected from baseline evaluation and follow-up, and 5-year estimated SCD risk was calculated (HCM Risk-Kids).

RESULTS

MLVWT Z score was <10 in 598 (58.1%), ≥10 to <20 in 334 (31.1%), and ≥20 in 143 (13.3%). Higher MLVWT Z scores were associated with heart failure symptoms, unexplained syncope, left ventricular outflow tract obstruction, left atrial dilatation, and nonsustained ventricular tachycardia. One hundred twenty-two patients (71.3%) with MLVWT Z score ≥20 had coexisting risk factors for SCD. Over a median follow-up of 4.9 years (interquartile range, 2.3-9.3), 115 (10.7%) had an SCD event. Freedom from SCD event at 5 years for those with MLVWT Z scores <10, ≥10 to <20, and ≥20 was 95.6%, 87.4%, and 86.0, respectively. The estimated SCD risk at 5 years had a nonlinear, inverted U-shaped relationship with MLVWT Z score, peaking at Z score +23. The presence of coexisting risk factors had a summative effect on risk.

CONCLUSIONS

In children with HCM, an inverted U-shaped relationship exists between left ventricular hypertrophy and estimated SCD risk. The presence of additional risk factors has a summative effect on risk. While MLVWT is important for risk stratification, it should not be used either as a binary variable or in isolation to guide implantable cardioverter defibrillator implantation decisions in children with HCM.

Outcomes and management of arrhythmogenic right ventricular cardiomyopathy in pregnancy: a case report

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disease with an estimated prevalence of up to 1:5000 in the general population. Few cases of ARVC during pregnancy are described in literature.

Case summary

A 32-year-old primigravida was referred to our clinic during the 32nd gestational week. Arrhythmogenic right ventricular cardiomyopathy diagnosis with biventricular involvement was made according to Task Force criteria. Beta-blocker therapy was started and an elective caesarean section was planned, during the 37th gestational week; no complications occurred. Thirteen months after delivery, the patient was readmitted in our hospital due to an episode of pre-syncope and after team discussion, an implantable cardioverter-defibrillator (ICD) was implanted.

Discussion

This case suggests that the absence of signs and symptoms of heart failure (HF) at a first evaluation plays a major role to predict maternal and foetal outcome in ARVC. Our experience is consistent with the evidence that indicates a favourable outcome in asymptomatic patients treated with optimal medical therapy during pregnancy. In our case, despite no major HF or arrhythmic complications during pregnancy, delivery, and puerperium, we observed an arrhythmic disease progression more likely independent from pregnancy, leading to ICD implantation.

Biventricular Arrhythmogenic Cardiomyopathy: a paradigmatic case

<p>We present a case of arrhythmogenic cardiomyopathy with biventricular involvement and strong&nbsp;arrhythmic substrate, highlighting&nbsp;the need to consider more than a single diagnostic option when facing arrhythmic presentations in young patients&nbsp;and&nbsp;the growing contribution provided by the genetic laboratory and contrast CMR to clinical management.</p>

[CircuLite Synergy ventricular assist device: a new approach to end-stage congestive heart failure]

BACKGROUND

The Synergy system, a miniature partial circulatory support device, is implanted by an off-pump, minimally invasive surgical approach. The system has been optimized to improve performance in an EU clinical trial for chronic ambulatory heart failure. This therefore offers the possibility of treating elderly chronic heart failure patients who might not usually be considered for long-term circulatory support.

METHODS

From June 2007 to December 2012, 63 patients were implanted with the Synergy system (12 patients ≥70 years) using four different releases of the device. Briefly, the system draws blood through the inflow cannula from the left atrium into the micro-pump (placed in a right subclavicular pocket) and pumps it through an outflow graft to the right subclavian artery. In this paper, we present an intermediate analysis of the clinical trial as performed on April 30, 2013, leading to the placing of the CE mark.

RESULTS

Mean duration of support is ongoing at 230 days (range 23-1387). Follow-up showed improved hemodynamic response, with additional improvements in 6-min walk distance (299 ± 144 to 420 ± 119 m) and Minnesota Living with Heart Failure Questionnaire (69.5 ± 20.4 to 49.2 ± 24.3). Older patients had longer mean durations of support (337 vs 188 days). On average, elderly and younger patients showed similar improvements in hemodynamics and 6-min walk distance (107 ± 120 vs 130 ± 121 m). Major adverse cardiac events included bleeding (n=4) with one bleeding related to renal failure resulting in death.

CONCLUSIONS

Clinical use of the Synergy device was associated with a significant functional improvement. Very low adverse event rates were reported with the latest device release. Older patients had smaller body sizes and worse renal function than younger patients. Both groups experienced similar hemodynamic benefits and functional improvements. The risk of bleeding and renal dysfunction appears to be increased in the elderly, though still within acceptable ranges compared to other full support devices. Minimally invasive long-term circulatory support devices, like Synergy, offer a new treatment option that might be available even for the elderly chronic heart failure population.

RAGE gene polymorphism in heart failure patients with and without angiographic evidence of significant coronary atherosclerosis

Heart failure (HF) is a multifactorial disorder in which clinical, environmental and genetic components take part. For this reason it is possible that common gene variants could affect development, progression and response to pharmacological therapy. In recent years the role of AGEs in the pathogenesis of cardiovascular diseases has become recognized but little is known about the role of the AGE–RAGE system in heart failure. The aim of the present study was to identify possible relationship between -374 T/A RAGE gene polymorphism with heart failure. The population in this study consists of 386 subjects with HF, selected according to the presence of depressed Left Ventricular Ejection Fraction (LVEF) less than45 percent, and 639 patients with CAD documented at coronary angiography. Within the population with HF there are 228 patients with disease secondary to not ischemic cause and 158 with post-ischemic condition. The sample of AA genotype was significantly lower in patients with post-ischemic HF in respect to HF secondary to non-ischemic causes (pless than0.001). A significant difference between the two groups was also observed regarding the allele frequency. In addition, differences in the allelic and the genotypic frequencies of homozygous genotypes were found between the HF patients free from evidence of coronary significant lesions and patients with at least one hemodynamically significant coronary lesion, both HF and CAD. In patients with at least one vessel compromised the presence of A allele and the homozygous AA genotype were significantly lower than in patients with lesion-free coronary. In conclusion, our research reveals that the -374 T/A polymorphism is related to the genesis of atherosclerotic coronary artery disease but not to its evolution. The protective role of AA genotype in respect to atheromatous disease is therefore confirmed also in the HF population with non-ischemic origin.

Primary headache and silent myocardial ischemia in patients with coronary artery disease

OBJECTIVE

The mechanisms by which migraine is linked to ischemic vascular disease remain uncertain and are likely to be complex. The aim of this study was to investigate the correlation between silent myocardial ischemia (SMI) and a history of documented primary headache in a large population of patients with exercise-induced myocardial ischemia.

METHODS

The study involved 1,427 consecutive patients (918 symptomatic and 509 asymptomatic patients) with exercise-induced myocardial ischemia and documented coronary artery disease (CAD).

RESULTS

Patients with anginal symptoms during exercise-induced myocardial ischemia had a significantly higher prevalence of primary headache than those without (41 vs. 30%, p < 0.001). Patients with angina pectoris in daily life also had greater prevalence of primary headache than those without anginal symptoms (37 vs. 20%; p < 0.0001). Symptomatic patients during percutaneous transluminal coronary angiography or myocardial infarction had a greater prevalence of primary headache than asymptomatic patients (p < 0.001 and p = 0.005, respectively).

CONCLUSIONS

Our data suggest that a history of headache in CAD population is correlated to a high probability of anginal symptoms and a decreased probability of SMI. The anamnestic absence of headache requires a close monitoring for patients with risk factors for CAD, because this population seems to have a lower susceptibility to pain and the risk of developing SMI might be increased.

The long-term survival and the risks and benefits of implantable cardioverter defibrillators in patients with hypertrophic cardiomyopathy

OBJECTIVE

Implantable cardioverter defibrillators (ICDs) are routinely used to prevent sudden cardiac death (SCD) in selected hypertrophic cardiomyopathy (HCM) patients, but the determinants of device-related complications, therapies and long-term cardiovascular mortality in ICD recipients are not known.

DESIGN

Retrospective observational cohort study.

SETTING

Single-centre tertiary referral cardiomyopathy clinic. Patients 334 consecutively evaluated HCM patients (median age 40 years, 62% male, 92% primary prevention) at risk of SCD treated with ICD. Thirty-six patients (11%) received concurrent cardiac resynchronisation therapy for heart failure symptoms.

RESULTS

During the 1286 patient-years of follow-up, cardiovascular mortality (including transplantation) occurred in 22 (7%) patients (1.7%/year) and was associated with New York Heart Association (NYHA) class III/IV (adjusted HR=9.38, 95% CI 3.31 to 26.55, p≤0.001), percentage fractional shortening (HR=0.92, 95% CI 0.87 to 0.96, p=0.001) and implantation for secondary prevention (HR=0.07, 95% CI 0.01 to 0.86, p=0.04). There were no SCD. Twenty-eight (8%) patients received appropriate shocks (2.3%/year), which were predicted by baseline fractional shortening (HR=0.96, 95% CI 0.92 to 0.99, p=0.04). Fifty-five (16%) patients received inappropriate shocks (4.6%/year). Sixty (18%) patients experienced implant-related complications (5.1%/year), including two deaths. Adverse ICD-related events (inappropriate shocks and/or implant complications) were seen in 101 (30%) patients (8.6%/year). Patients with cardiac resynchronisation therapy were more likely to develop implant complications than those with single-chamber ICDs (HR=4.39, 95% CI 1.44 to 13.35, p=0.009) and had a higher 5-year cardiovascular mortality than did the rest of the cohort (21% vs 6%, p<0.001).

CONCLUSIONS

HCM patients with an ICD have a significant cardiovascular mortality and are exposed to frequent inappropriate shocks and implant complications. These data suggest that new strategies are required to improve patient selection for ICDs and to prevent disease progression in those that receive a device.

A novel Val734Ile variant in the ABCC9 gene associated with myocardial infarction

BACKGROUND

Alterations in coronary vasomotor tone are deemed to play an important role in myocardial infarction (MI), and the ATP-binding cassette transporter C9-ABCC9-may be involved in the regulation of coronary artery vasomotility. We sought to determine whether genetic variations in the coding sequence of ABCC9 gene could be associated with precocious MI (myocardial infarction before the age of 60 years) in humans.

METHODS

In this study, we screened using PCR-SSCP analysis the entire coding region of the ABCC9 gene in 45 patients with precocious MI and 45 age- and gender-matched controls.

RESULTS

A novel missense mutation, Val734Ile in exon 17, was detected in one MI patient. We therefore analyzed by PCR-RFLPs the frequency of this nonsynonymous change in a large Italian cohort of precocious MI patients (n=584) and healthy comparison subjects (n=873). After allowance for the potential confounding effects of age, gender, and established cardiovascular risk factors, multivariate logistic regression analysis revealed that carriers of the rare 734Ile allele would have a 6.40-fold risk of suffering MI before the age of 60 years as compared to controls (95% CI=1.58-25.90, P=0.009).

CONCLUSIONS

Taken together, our results provide the first important evidence that the newly discovered 734Ile allele in ABCC9 might influence susceptibility to precocious MI in our population.

Prognostic significance of plasma osteopontin levels in patients with chronic stable angina

AIMS

Levels of the secreted glycophosphoprotein osteopontin (OPN) have been associated with the presence and extent of coronary artery disease (CAD). The present study assessed the relationship between plasma OPN concentrations and prognosis in patients with chronic stable angina (CSA).

METHODS AND RESULTS

OPN was measured in baseline plasma samples from 799 patients with stable angina pectoris and angiographically documented CAD. Participants were prospectively followed-up for a median of 2.7 years (maximum 4.1 years). The primary study endpoint was the composite of non-fatal myocardial infarction and death from cardiovascular causes. In the univariate Cox proportional hazard analysis, the log-transformed OPN level [hazard ratio (HR) 1.79, 95% CI 1.35-2.36, P < 0.001] was significantly related to adverse outcome. In addition, hypertension, levels of C-reactive protein, and statin use were associated with future adverse events. Levels of OPN (HR, 1.88; P < 0.001) and C-reactive protein (HR, 1.42; P = 0.003), as well as the presence of hypertension (HR, 2.39; P = 0.008) remained statistically significant, independent predictors of adverse cardiovascular outcome in a multivariable Cox proportional hazard analysis.

CONCLUSION

Baseline levels of OPN are an independent predictor of future adverse cardiac events in patients with CSA and may be useful for risk stratification.

Decreased plasma levels of soluble receptor for advanced glycation end-products in patients with essential hypertension

OBJECTIVES

Advanced glycation end-products (AGE) may cause vascular stiffening by forming crosslinks through the collagen molecule or by interaction with their cellular transductional receptor (RAGE). A secreted isoform of RAGE, termed soluble RAGE (sRAGE), may contribute to the removal/detoxification of AGE by acting as a decoy. Here we studied the plasma sRAGE levels in hypertensive and normotensive human subjects. We also investigated the relationship between blood pressure parameters and plasma sRAGE concentrations.

DESIGN

A cross-sectional case-control study.

SETTING AND PARTICIPANTS

The outpatient clinic of a university teaching hospital. Participants were 147 never-treated patients with essential hypertension (87 men and 60 women, aged 50 +/- 10 years) and 177 normotensive controls (118 men and 59 women, aged 49 +/- 10 years).

MAIN OUTCOME MEASURES

Plasma sRAGE levels determined by enzyme-linked immunosorbent assay, systolic blood pressure (SBP), diastolic blood pressure, pulse pressure (PP) and mean arterial pressure.

RESULTS

The plasma concentration of sRAGE [median (interquartile range)] was 1206 (879-1658) pg/ml in hypertensive subjects and 1359 (999-2198) pg/ml in normotensive controls (P = 0.002). Simple correlation analysis revealed that log-transformed sRAGE levels were inversely correlated with SBP (r = -0.11; P < 0.001) and PP (r = -0.23; P < 0.001). Forward-selection multiple regression analysis revealed that log-transformed sRAGE levels were determined more strongly by PP (F = 3.127, P < 0.001).

CONCLUSIONS

Plasma sRAGE levels are decreased in patients with essential hypertension and are inversely related to PP. Our results raise the possibility that sRAGE may play a role in arterial stiffening and its complications.