Role of Titin Missense Variants in Dilated Cardiomyopathy

BACKGROUND

The titin gene (TTN) encodes the largest human protein, which plays a central role in sarcomere organization and passive myocyte stiffness. TTN truncating mutations cause dilated cardiomyopathy (DCM); however, the role of TTN missense variants in DCM has been difficult to elucidate because of the presence of background TTN variation.

METHODS AND RESULTS

A cohort of 147 DCM index subjects underwent DNA sequencing for 313 TTN exons covering the N2B and N2BA cardiac isoforms of TTN. Of the 348 missense variants, we identified 44 "severe" rare variants by using a bioinformatic filtering process in 37 probands. Of these, 5 probands were double heterozygotes (additional variant in another DCM gene) and 7 were compound heterozygotes (2 TTN "severe" variants). Segregation analysis allowed the classification of the "severe" variants into 5 "likely" (cosegregating), 5 "unlikely" (noncosegregating), and 34 "possibly" (where family structure precluded segregation analysis) disease-causing variants. Patients with DCM carrying "likely" or "possibly" pathogenic TTN "severe" variants did not show a different outcome compared with "unlikely" and noncarriers of a "severe" TTN variant. However, the "likely" and "possibly" disease-causing variants were overrepresented in the C-zone of the A-band region of the sarcomere.

CONCLUSIONS

TTN missense variants are common and present a challenge for bioinformatic classification, especially when informative families are not available. Although DCM patients carrying bioinformatically "severe" TTN variants do not appear to have a worse clinical course than noncarriers, the nonrandom distribution of "likely" and "possibly" disease-causing variants suggests a potential biological role for some TTN missense variants.

Insights from Cardiac Mechanics after Three Decades from Successfully Repaired Aortic Coarctation

BACKGROUND AND AIMS

Patients who underwent a successful repair of the aortic coarctation show chronic hyperdynamic state and normal left ventricular (LV) geometry; however, there are few data regarding the LV systolic function in the long term. Accordingly, we assessed LV systolic mechanics and factors associated with LV systolic dysfunction (LVSD) in patients with repaired CoA.

METHODS

Clinical and echocardiographic data from 19 repaired CoA were analyzed 28 ± 13 years after surgery. Stress-corrected midwall shortening (sc-MS) and mitral annular peak systolic velocity (S') were analyzed as indexes of LV circumferential and longitudinal systolic function, respectively. Echocardiographic data of CoA patients were compared with 19 patients matched for age and hypertension and 38 healthy controls. Sc-MS was considered impaired if <89%, S' if <8.5 cm/s (10th percentiles of healthy controls, respectively).

RESULTS

There were no statistical differences between study groups in LV volumes, mass and geometry. LV ejection fraction and Sc-MS were similar in all groups, however, CoA group had a significantly lower peak S' in comparison with matched and healthy controls (7.1 ± 1.3, 10.3 ± 1.9, and 11.1 ± 1.5, respectively; all P < 0.001). Prevalence of longitudinal LVSD defined as low S' was 84% in CoA, 13% in matched, and 5% in healthy control group (all P<0.05). Multivariate logistic regression analysis revealed that low peak S' was independently related to higher E/E' ratio and the presence of CoA.

CONCLUSIONS

Patients who underwent a successful repair of CoA commonly show asymptomatic longitudinal LVSD associated with worse LV diastolic function in the long-term follow-up.

Arrhythmogenic Phenotype in Dilated Cardiomyopathy: Natural History and Predictors of Life-Threatening Arrhythmias

BACKGROUND

Patients with dilated cardiomyopathy (DCM) may present with ventricular arrhythmias early in the disease course, unrelated to the severity of left ventricular dysfunction. These patients may be classified as having an arrhythmogenic DCM (AR-DCM). We investigated the phenotype and natural history of patients with AR-DCM.

METHODS AND RESULTS

Two hundred eighty-five patients with a recent diagnosis of DCM (median duration of the disease 1 month, range 0 to 7 months) and who had Holter monitoring at baseline were comprehensively evaluated and followed for 107 months (range 29 to 170 months). AR-DCM was defined by the presence of ≥1 of the following: unexplained syncope, rapid nonsustained ventricular tachycardia (≥5 beats, ≥150 bpm), ≥1000 premature ventricular contractions/24 hours, and ≥50 ventricular couplets/24 hours, in the absence of overt heart failure. The primary end points were sudden cardiac death (SCD), sustained ventricular tachycardia (SVT), or ventricular fibrillation (VF). The secondary end points were death from congestive heart failure or heart transplantation. Of the 285 patients, 109 (38.2%) met criteria for AR-DCM phenotype. AR-DCM subjects had a higher incidence of SCD/SVT/VF compared with non-AR-DCM patients (30.3% vs 17.6%, P=0.022), with no difference in the secondary end points. A family history of SCD/SVT/VF and the AR-DCM phenotype were statistically significant and cumulative predictors of SCD/SVT/VF.

CONCLUSIONS

One-third of DCM patients may have an arrhythmogenic phenotype associated with increased risk of arrhythmias during follow-up. A family history of ventricular arrhythmias in DCM predicts a poor prognosis and increased risk of SCD.

Acute Hemodynamic Response to Cardiac Resynchronization in Dilated Cardiomyopathy: Effect on Late Mitral Regurgitation

BACKGROUND

Functional mitral regurgitation (FMR) is associated with reduced survival in dilated cardiomyopathy (DCM). Cardiac resynchronization therapy (CRT) can improve FMR. We sought to identify the predictors of FMR improvement after CRT in DCM.

METHODS

From January 2003 to December 2013, 430 DCM patients consecutively enrolled were retrospectively analyzed. Inclusion criteria were successful CRT implantation in the presence of conventional indications (i.e., left bundle branch block, left ventricular ejection fraction ≤35%, New York Heart Association functional class ≥II) and moderate-to-severe FMR at the time of procedure. Early echocardiographic evaluation after CRT implantation (median 2.5 days) has been performed in each patient. Improvement in FMR (absent/mild) at midterm (7 months; interquartile range 4-10) was considered as the primary study end point.

RESULTS

A total of 44 patients (10% of the overall cohort) were included. A significant reduction in FMR severity was observed in 21 patients (48%) at midterm after CRT (median time 7 months). No preimplantation variables predicted FMR evolution, but FMR improvement at midterm was strongly predicted by an acute favorable hemodynamic response (persistence/development of normal right ventricular function and 10-mm Hg decrease or normalization [≤35 mm Hg] of systolic pulmonary artery pressure) at postimplantation echocardiography (odds ratio: 13.7; 95% confidence interval: 1.27-42.8; P = 0.016). FMR improvement at midterm was stable during follow-up and was associated with superior long-term transplant-free survival (P = 0.022).

CONCLUSIONS

Stable FMR improvement frequently occurs after CRT implantation in DCM and is associated with improved transplant-free survival. Echocardiographic evaluation of acute hemodynamic response to CRT is helpful to early identification of the favorable FMR evolution.

[Achieving optimal cholesterol levels in patients with chronic ischemic heart disease: from guidelines to the real world]

BACKGROUND

It is known that less than half of patients with coronary heart disease reaches the target of LDL cholesterol (LDL-C) <100 mg/dl. According to the latest international guidelines, this target has been lowered to <70 mg/dl in very high-risk patients.

METHODS

From November 1, 2009 to December 31, 2012, 4953 patients with coronary heart disease were enrolled in the Cardiovascular Registry of Trieste (Italy). We assessed clinical data, LDL-C levels, statin prescription and medium-term outcome in patients with coronary heart disease.

RESULTS

At first clinical evaluation, LDL-C values were available for only 61.5% of patients. The target level of LDL-C <70 mg/dl was reached in 17% of cases and LDL-C <100 mg/dl in 53%. Patients with lower LDL-C levels were more frequently males, with higher cardiovascular risk profile, more comorbidity and more frequent polypharmacy. LDL-C levels influenced statin prescription: in patients with LDL-C ≥ 100 mg/dl, cardiologists started or modified the dosage of statin therapy twice more than in patients with LDL-C <100 mg/dl, even if only in less than 20% of cases. Patients with LDL-C <100 mg/dl in statin therapy had better prognosis, whereas patients with low LDL-C levels without statin therapy had the worst prognosis. Other prognostic factors in this population with LDL-C <100 mg/dl were age, presence of heart failure, comorbidities (evaluated with Charlson index) and polypharmacy.

CONCLUSIONS

In our population of outpatients with coronary heart disease, the target of LDL-C <100 mg/dl was reached in 53% of cases. LDL-C levels influenced statin prescription and modification of dosages. The medium-term outcome is closely influenced by the achievement of target LDL-C levels and statin prescription.

[Nonvalvular atrial fibrillation: data from the Observatory of Cardiovascular Diseases in the province of Trieste (Italy)]

BACKGROUND

Nonvalvular atrial fibrillation (NVAF) is the most common arrhythmia in outpatients and is associated with increased mortality, thromboembolic and hemorrhagic events. Although several international studies have evaluated its prognostic impact in the real world, Italian data are still lacking. Our aim was to define the prevalence, comorbidity, treatment and outcome in a population of "real-life" outpatients with NVAF.

METHODS

From 2009 to 2013, 21 282 consecutive patients referred to the Cardiovascular Center of Trieste were enrolled in the study. NVAF was defined in the absence of moderate-to-severe valvular disease, valvular interventions, rheumatic heart disease. Events evaluated in the follow-up included mortality, hospitalizations, thromboembolism and hemorrhage. Clinical data and events were derived from the cardiac regional electronic patient records and the ICD-9 hospital discharge records.

RESULTS

3379 patients (15.8%) had NVAF (35.6% paroxysmal, 34.5% persistent, 29.9% permanent); compared to the general population these patients were older, predominantly male, with hypertension, diabetes and history of stroke/transient ischemic attack and heart failure. Oral anticoagulant therapy was prescribed in 54% of cases, above all in persistent or permanent forms, in patients with higher CHA2DS2-VASc score and younger age. The rate of all-cause mortality, cardiovascular hospitalization, thromboembolic and hemorrhagic events during follow-up was higher in patients with NVAF than in the general population. The use of oral anticoagulant therapy reduced the incidence of thromboembolic events. CHA2DS2-VASc score emerged as an independent predictor of thromboembolic events in patients with paroxysmal (35% higher risk), persistent (40% higher risk) and permanent atrial fibrillation (34% higher risk than patients without atrial fibrillation).

CONCLUSIONS

In "real-life" outpatients NVAF is associated with older age, more comorbidities and increased cardiovascular events. CHA2DS2-VASc and HAS-BLED scores predict accurately the risk for thromboembolic and hemorrhagic events. Oral anticoagulation reduces thromboembolic events, but its use is limited to just half of the patients.

Early improvement of functional mitral regurgitation in patients with idiopathic dilated cardiomyopathy

The aim of the study was to assess the clinical and prognostic impact of early functional mitral regurgitation (FMR) improvement on the outcome of patients with idiopathic dilated cardiomyopathy (IDC). The prevalence and prognostic role of FMR improvement, particularly at early follow-up, in patients with IDC are still unclear. From 1988 to 2009, we enrolled 470 patients with IDC with available FMR data at baseline and after 6 ± 2 months. According to the evolution of FMR, patients were classified into 3 groups: stable absent-mild FMR, early FMR improvement (downgrading from moderate-severe to absent-mild), and persistence/early development of moderate-severe FMR. At baseline, 177 of 470 patients (38%) had moderate-severe FMR. Patients with early FMR improvement had significantly better survival rate-free from heart transplant with respect to those with persistence/early development of moderate-severe FMR (93%, 81%, and 66% vs 91%, 64%, and 52% at 1, 6, and 12 years, respectively; p = 0.044). At 6-month follow-up multivariate analysis, FMR improvement was associated with better prognosis (hazard ratio 0.78, 95% confidence interval [CI] 0.64 to 0.96, p = 0.02); the other independent predictors were male gender, heart failure duration, and early re-evaluation of the New York Heart Association class and left ventricle systolic function. This model provided more accurate risk stratification compared with the baseline model (Net Reclassification Index 80% at 12 months and 41% at 72 months). In conclusion, in a large cohort of patients with IDC receiving optimal medical treatment, early improvement of FMR was frequent (53%) and emerged as a favorable independent prognostic factor with an incremental short- and long-term power compared with the baseline evaluation.

Persistent recovery of normal left ventricular function and dimension in idiopathic dilated cardiomyopathy during long‐term follow‐up: does real healing exist?

Background

An important number of patients with idiopathic dilated cardiomyopathy have dramatically improved left ventricular function with optimal treatment; however, little is known about the evolution and long‐term outcome of this subgroup, which shows apparent healing. This study assesses whether real healing actually exists in dilated cardiomyopathy .

Methods and Results

Persistent apparent healing was evaluated among 408 patients with dilated cardiomyopathy receiving tailored medical treatment and followed over the very long‐term. Persistent apparent healing was defined as left ventricular ejection fraction ≥50% and indexed left ventricular end‐diastolic diameter ≤33 mm/m² at both mid‐term (19±4 months) and long‐term (103±9 months) follow‐up. At mid‐term, 63 of 408 patients (15%) were apparently healed; 38 (60%; 9% of the whole population) showed persistent apparent healing at long‐term evaluation. No predictors of persistent apparent healing were found. Patients with persistent apparent healing showed better heart transplant–free survival at very long‐term follow‐up (95% versus 71%; P=0.014) compared with nonpersistently normalized patients. Nevertheless, in the very long term, 37% of this subgroup experienced deterioration of left ventricular systolic function, and 5% died or had heart transplantation.

Conclusions

Persistent long‐term apparent healing was evident in a remarkable proportion of dilated cardiomyopathy patients receiving optimal medical treatment and was associated with stable normalization of main clinical and laboratory features. This condition can be characterized by a decline of left ventricular function over the very long term, highlighting the relevance of serial and individualized follow‐up in all patients with dilated cardiomyopathy, especially considering the absence of predictors for long‐term apparent healing.

Combined circumferential and longitudinal left ventricular systolic dysfunction in patients with asymptomatic aortic stenosis

BACKGROUND

Early detection of left ventricular (LV) systolic dysfunction is pivotal in the management of patients with aortic stenosis (AS). LV circumferential and/or longitudinal shortening may be impaired in these patients despite LV ejection fraction is preserved. We focused on prevalence and factors associated with combined impairment of circumferential and longitudinal shortening (C&L) in asymptomatic AS patients.

METHODS

Echocardiographic and clinical data from 200 patients with asymptomatic AS of any degree without history of heart failure and normal LV ejection fraction were analyzed. C&L were evaluated by mid-wall shortening (MS) and tissue Doppler mitral annular peak systolic velocity (S'), and classified low if <16.5% and if <8.5 cm/sec, respectively (10th percentiles of controls).

RESULTS

Combined C&L dysfunction was detected in 72 patients (36%). The variables associated with this condition were higher LV mass (OR 1.02 [CI 1.01-1.04], P = 0.03), concentric LV geometry (OR 4.30 [CI 1.79-10.34], P = 0.001), increasing pulmonary artery wedge pressure (by E/e' ratio; OR 1.11 [CI 1.04-1.19], P = 0.001). The relation of MS and peak S' was linear and slightly significant in the whole population (r = 0.23; F statistic=0.001), absent in patients with C&L dysfunction (r = 0.04; F = ns), negative (linear model) in the subgroup of patients without C&L dysfunction (r = -0.22; F = 0.02).

CONCLUSIONS

C&L dysfunction is present in more than one-third of patients with asymptomatic AS and is associated with concentric LV geometry and higher degree of diastolic dysfunction. The relation between MS and peak S' largely varies in the subgroups with different C&L function.

Effects of estroprogestins containing natural estrogen on vaginal flora

Estroprogestins with "natural oestrogen" has represented a new option in terms of combined hormonal contraception. So, the aim of this study is to investigate how estroprogestins with natural estrogen may modify the vaginal niche. In literature, very few studies focused on the interaction between hormonal contraception and vaginal milieu. This is a prospective comparative study. We enrolled 60 women from January 2013 to September 2013, 30 of them were administered estradiol valerate dienogest (E2V+DNG - Klaira®) in a quadriphasic regimen, while the other 30 women were administered 17-β estradiol with nomestrol acetate (EV+NOMAC - Zoely®) in a monophasic regimen. After a baseline study of vaginal milieu at recruitment of patients (Gram stain with Nugent score, vaginal pH, vaginal wet mount for the quantification of leukocytes, Lactobacilli and/or presence of Candida), we performed the same follow-up after six months of estroprogestin therapy. Our results showed that the women treated with E2V+DNG had a trend of an improvement of vaginal health in terms of increase of lactobacillar flora and reduction of vaginal pH in place of women treated with EV+NOMAC that showed a reduction of cervical mucus. Finally, our data about the effects on vaginal flora exerted by two estroprogestin pills (EPs) containing a natural estrogen suggest slight, but interesting differences in terms of vaginal ecology. These differences could be related to the type of estrogen, type of progestin, regimen of administration and, after all, to the net balance between estrogenic and progestin component of the EPs.

Titin and desmosomal genes in the natural history of arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

Genotype-phenotype correlations are poorly characterised in arrhythmogenic right ventricular cardiomyopathy (ARVC). We investigated whether carriers of rare variants in desmosomal genes (DC) and titin gene (TTN) display different phenotypes and clinical outcomes compared with non-carriers (NT-ND).

METHODS AND RESULTS

Thirty-nine ARVC families (173 subjects, 67 affected) with extensive follow-up (mean 9 years), prospectively enrolled in the International Familial Cardiomyopathy Registry since 1991, were screened for rare variants in TTN and desmosomal genes (DSP, PKP2, DSG2, DSC2). Multiple clinical and outcome variables were compared between three genetic groups (TTN, DC, NT-ND) to define genotype-phenotype associations. Of the 39 ARVC families, 13% (5/39) carried TTN rare variants (11 affected subjects), 13% (5/39) DC (8 affected), while 74% (29/39) were NT-ND (48 affected). When compared with NT-ND, DC had a higher prevalence of inverted T waves in V2-3 (75% vs 31%, p=0.004), while TTN had more supraventricular arrhythmias (46% vs 13%, p=0.013) and conduction disease (64% vs 6% p<0.001). When compared with the NT-ND group, the DC group experienced a worse prognosis (67% vs 11%, p=0.03) and exhibited a lower survival free from death or heart transplant (59% vs 95% at 30 years, and 31% vs 89% at 50 years, HR 9.66, p=0.006), while the TTN group showed an intermediate survival curve (HR 4.26, p=0.037).

CONCLUSIONS

TTN carriers display distinct phenotypic characteristics including a greater risk for supraventricular arrhythmias and conduction disease. Conversely, DC are characterised by negative T waves in anterior leads, severe prognosis, high mortality and morbidity.

Reasons why patients suffering from chronic heart failure at very high risk for death survive

BACKGROUND

An accurate prognostic stratification is essential for optimizing the clinical management and treatment decision-making of patients with chronic heart failure (HF). Among the best available models, we used the Cardiac and Comorbid Conditions HF (3C-HF) Score, to predict all-cause mortality in patients with CHF.

METHODS

we selected and characterized the subgroup of patients at very high risk with the worst mid-term prognosis belonging to the highest decile of 3C-HF score with the aim to assess predictors of survival in subjects with an expected probability of 1-year mortality near to 45%.

METHODS AND RESULTS

We recruited 1777 consecutive chronic HF patients at 3 Italian Cardiology Units. Median age was 76 ± 10 years, 43% were female, and 32% had preserved ejection fraction. Subjects belonging to the highest decile of 3C-HF score were 246 (13.8% of total population). During a median follow-up of 21 [12-40] months, 110 of these patients (45%) survived and 136 (55%) died. The variables that contributed to survival prediction emerged by Cox regression multivariate analysis were the lower degree of renal dysfunction and higher body mass index.

CONCLUSIONS

The prognostic stratification of chronic HF patients allows in daily practice to select patients at different risk for death and identify prognosticators of survival in outliers at very high risk of death. The reasons why these patients outlive the matching part of subjects who expectedly die are related to the maintenance of a satisfactory renal function and body mass index.

Long-term prognostic impact of therapeutic strategies in patients with idiopathic dilated cardiomyopathy: changing mortality over the last 30 years

AIMS

ACE-inhibitors, β-blockers, implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy (CRT) improved prognosis of heart failure. We sought to analyse the long-term prognostic impact of evidence-based integrated therapeutic strategies in patients with idiopathic dilated cardiomyopathy (IDCM).

METHODS AND RESULTS

From 1978 to 2007, 853 IDCM patients (45 ± 15 years, 72% males) were enrolled and classified as follows: Group 1, 110 patients (12.8%) enrolled during 1978-1987; Group 2, 376 patients (44.1%) enrolled during 1988-1997; Group 3, 367 patients (43.1%) enrolled during 1998-2007. ACE-inhibitors/angiotensin receptor blockers were administered in 34%, 93%, and 93% (P <0.001), and β-blockers in 11%, 82%, and 86% (P <0.001) in Groups 1, 2, and 3, respectively; ICDs were implanted in 2%, 14%, and 13% (P = 0.005); mean time to device implantation was lower in Group 3. At 8 years, heart transplant (HTx)-free survival rates were 55%, 71%, and 87% in Groups 1, 2, and 3, respectively (P <0.001). Similar progressive improvement was found for pump-failure death (DHF)/HTx, while survival free from sudden death (SD) was significantly improved only in Group 3. Multivariable models considering competing risk indicated early diagnosis (i.e. a baseline less advanced disease stage) and tailored medical therapy (HR 0.44, CI 95% 0.19-0.98) as independent protectors against DHF/HTx. Concerning SD, lower left ventricular ejection fraction emerged as a predictor, while ICD was the only therapy with a protective role (HR 0.08, CI 95% 0.01-0.61). Treatment with digitalis emerged as a predictor of both DHF/HTx and SD.

CONCLUSIONS

An effective management and evidence-based integrated therapeutic approach progressively and significantly improved the long-term prognosis of IDCM during the last three decades.

Long-term outcome of 'super-responder' patients to cardiac resynchronization therapy

AIMS

To evaluate the long-term changes of clinical and echocardiographic parameters, the incidence of cardiac events and parameters associated with late cardiac events in 'super-responders' to cardiac resynchronization therapy (CRT) with [CRT defibrillator (CRT-D)] or without defibrillator back-up.

METHODS AND RESULTS

In all consecutive patients treated with CRT in two Italian centres (Trieste and Udine) with left ventricular ejection fraction (LVEF) ≤0.35 at implantation (Timp) and LVEF > 0.50 1 and/or 2 years (Tnorm) after implantation, the long-term outcome and the evolution of echocardiographic parameters were assessed; factors associated with a higher risk of cardiac events, defined as hospitalization or death for heart failure (HF), sudden death, or CRT-D appropriate interventions, were also analysed. Among the 259 patients evaluated, 62 (24%) had LVEF ≥ 0.50 at Tnorm (n = 44 with at 1 year, n = 18 at 2 years). During a mean follow-up of 68 ± 30 months, one cardiac death (for HF) and eight cardiovascular events (two hospitalization for HF and six appropriate CRT-D interventions) occurred. At the last echo evaluation (Tfup) performed 51 ± 26 months after Timp, LVEF was <0.50 in five patients (>0.45 in four of them). At univariable analysis, only LV end-systolic volume evaluated at Tfup was associated with a higher risk of cardiac events during follow-up.

CONCLUSION

In 'super-responders' to CRT long-term outcome is excellent. However, cardiac events, mainly CRT-D appropriate interventions, can occur despite the persistence of LVEF > 0.50. Early identification of these patients is still an unsolved issue.