P-wave duration in lead aVR and the risk of atrial fibrillation in hypertension.

BACKGROUND: Hypertension entails atrial remodeling that affect P-wave (PW) duration on electrocardiogram (ECG). PW indices (e.g., variance, dispersion, and terminal force) are associated with a higher risk for atrial fibrillation (AF), but their calculation requires multiple measurements of PW duration, limiting their use in clinical practice. We evaluated whether PW duration in specific ECG leads may identify patients with increased susceptibility to AF in a population of hypertensive patients. METHODS: In a case-control study, AF and control subjects were matched for age, sex, and left atrial (LA) dimensions. PW duration was measured from digitally stored ECGs. Logistic regression was used to assess the association of PW duration and indices with AF. RESULTS: We enrolled 44 hypertensive AF patients (16 paroxysmal and 28 persistent) and 44 hypertensive controls. AF and control subjects were matched for sex (males, n = 27), age (67 ± 8 years), LA diameter (40 ± 5 mm), and were comparable for left ventricular mass (45 ± 11 g/m(2.7) vs 48 ± 12 g/m(2.7) , P = 0.19), ejection fraction (58 ± 7% in both groups), and prevalence of mild valvular heart disease (7% vs 5%; P = 0.64). PW duration in lead aVR was significantly higher in AF patients as compared with controls (115 ± 18 ms vs 101 ± 14 ms; P < 0.0001) and was the best independent predictor of AF in multivariable logistic regression (PW ≥ 100 ms: RR = 3.7; 95% CI: 1.3-10.3; P = 0.02). CONCLUSIONS: Simple measurement of PW duration in lead aVR allows effective identification of AF patients in a population of hypertensives. Confirmation of this finding in a larger population would provide a simple and effective risk marker of AF in hypertensive patients.

Extracellular matrix remodelling in myocardial hypertrophy and failure : focus on osteopontin.

Cardiac remodelling refers to molecular and cellular changes of the myocardium, as well as adapting alterations in size, shape and function of the heart in response to changing loading conditions. It represents the final common pathway of different heart diseases, and is recognized as a crucial aspect of cardiac and myocardial dysfunction and a well established determinant of the clinical course of heart failure.Osteopontin is an extracellular matrix glycoprotein secreted by osteoblasts, osteoclasts, macrophages, T cells, vascular smooth muscle cells, fibroblasts and cardiomyocytes. Osteopontin is not expressed in healthy cardiac tissue, although its expression can be triggered by pressure or volume overload, hypoxia and angiotensin II. Indeed, osteopontin has been reported in macrophages and interstitial tissues early after myocardial infarction and in cardiac macrophage-like cells of inflammatory lesions in experimental models of cardiomyopathy. Pressure overload is associated with osteopontin overexpression as well. Indeed, myocardial osteopontin messenger RNA is upregulated in rats following renovascular hypertension or aortic banding. In humans, a significant correlation exists between increased osteopontin immunoreactivity in cardiac myocytes and impaired left ventricular function or cardiomyocyte hypertrophy in patients with dilated cardiomyopathy.The present article focuses on the role of osteopontin in myocardial hypertrophy and remodelling. In general, evidence supports the concept that osteopontin plays a crucial role in extracellular matrix remodelling following myocardial adaptation to hypertrophic, inflammatory and neurohormonal stimuli in the overloaded heart.

A 34-year longitudinal study on long-term cardiac outcomes in DM1 patients with normal ECG at baseline at an Italian clinical centre.

Cardiac conduction and/or rhythm abnormalities (CCRA) are the most frequent and life-threatening complications in DM1. In order to determine prevalence, incidence, characteristics, age of onset and predictors of CCRA, CCRA progression and sudden cardiac death (SCD) in DM1, we collected ECG/24hECG-Holter data from a yearly updated 34-year database of a cohort of 103 DM1 patients without cardiac abnormalities at baseline, followed for at least 1 year. Fifty-five patients developed CCRA [39 developed conduction abnormalities (CCA) and 16 rhythm abnormalities (CRA)], which progressed in 22. Nine had SCD. Risk and incidence of CCRA amounted to 53.4 and 6.83% person-years (CCA: 37.9 and 4.8%; CRA 15.5 and 2%), respectively; risk and incidence of SCD amounted to 8.74 and 0.67% person-years, respectively. CTG expansion represented a predictor of CCRA incidence (HR 1.10, p = 0.04), CCRA progression (HR 1.28, p = 0.001) and SCD (HR 1.39, p = 0.002). MIRS progression during follow-up was associated with CCRA prevalence (OR 5.82, p = 0.004); older age and larger CTG expansion to SCD prevalence (OR 2.67, p = 0.012; OR 1.54, p = 0.005). Age of CCRA onset and CCRA progression was significantly lower in patients with larger CTG expansion and in those with MIRS progression. Age when SCD occurred was significantly lower in patients with larger CTG expansion. Amongst recorded cardiac abnormalities, both atrial flutter (OR 8.70; p = 0.031) and paroxysmal supraventricular tachycardia (OR 8.67; p = 0.040) were associated with SCD. Although all DM1patients may develop cardiac abnormalities at any time in their life, patients older than 30 years with larger CTG expansion and MIRS progression in particular should be carefully monitored via periodical ECG.

Common genetic variants in selected Ca²âº signaling genes and the risk of appropriate ICD interventions in patients with heart failure.

PURPOSE: Defective Ca²âº handling in failing cardiomyocites predisposes patients with heart failure (HF) to ventricular arrhythmia. We investigated whether gene variants of Ca²âº handling proteins are associated with the occurrence of ventricular tachycardia/fibrillation (VT/VF) in HF patients implanted with a primary prevention implantable cardioverter-defibrillator (ICD). METHODS: One hundred thirty-six patients with HF were followed from ICD implantation to the time of first appropriate ICD intervention for VT > 170 bpm. The following polymorphisms were genotyped: ATP2A2 rs1860561 and rs56243033; RYR2 rs4142933; CASQ2 rs4074536; SLC8A1 g.-23449C > A; PLN rs12198461; FKBP1B rs7568163. Hazard ratios (HR) were derived from Cox proportional-hazards regression analysis. RESULTS: After a mean follow-up of 879 days (IQ range, 327 to 1,459), 34 patients (25%) had appropriate ICD intervention. Non-sustained VT (HR, 2.12; 95%CI, 0.87-5.19; p = 0.09) and atrial fibrillation (AF) at ICD implantation (HR, 2.33; 95%CI, 0.89-6.10; p = 0.08) predicted appropriate ICD interventions with borderline statistical significance. Prevalence of ATP2A2 rs1860561 variant was 17% in patients without VT/VF and 4% in those with ventricular arrhythmia (p = 0.009). After adjustment for AF and NSVT, the rs1860561 A mutant allele independently predicted lower incidence of VT/VF (HR, 0.29; 95%CI, 0.09-0.98; p = 0.04). CONCLUSIONS: The observation that ATP2A2 rs1860561 gene variant associated with lower risk of life-threatening arrhythmia in HF patients suggests that selected calcium gene variants may modify the risk of SD even within the complex and polygenic pathological condition of HF. Combining traditional risk factors and genetic profiling could reveal helpful to identify HF patients who will benefit most from ICD implantation.

Atrial natriuretic Peptide single nucleotide polymorphisms in patients with nonfamilial structural atrial fibrillation.

BACKGROUND: Atrial natriuretic peptide (ANP) has antihypertrophic and antifibrotic properties that are relevant to AF substrates. The -G664C and rs5065 ANP single nucleotide polymorphisms (SNP) have been described in association with clinical phenotypes, including hypertension and left ventricular hypertrophy. A recent study assessed the association of early AF and rs5065 SNPs in low-risk subjects. In a Caucasian population with moderate-to-high cardiovascular risk profile and structural AF, we conducted a case-control study to assess whether the ANP -G664C and rs5065 SNP associate with nonfamilial structural AF. METHODS: 168 patients with nonfamilial structural AF and 168 age- and sex-matched controls were recruited. The rs5065 and -G664C ANP SNPs were genotyped. RESULTS: The study population had a moderate-to-high cardiovascular risk profile with 86% having hypertension, 23% diabetes, 26% previous myocardial infarction, and 23% left ventricular systolic dysfunction. Patients with AF had greater left atrial diameter (44 ± 7 vs. 39 ± 5 mm; P < 0.001) and higher plasma NTproANP levels (6240 ± 5317 vs. 3649 ± 2946 pmol/mL; P < 0.01). Odds ratios (ORs) for rs5065 and -G664C gene variants were 1.1 (95% confidence interval [CI], 0.7-1.8; P = 0.71) and 1.2 (95% CI, 0.3-3.2; P = 0.79), respectively, indicating no association with AF. There were no differences in baseline clinical characteristics among carriers and noncarriers of the -664C and rs5065 minor allele variants. CONCLUSIONS: We report lack of association between the rs5065 and -G664C ANP gene SNPs and AF in a Caucasian population of patients with structural AF. Further studies will clarify whether these or other ANP gene variants affect the risk of different subphenotypes of AF driven by distinct pathophysiological mechanisms.

Occurrence of hypotension in older participants. Which 24-hour ABPM parameter better correlate with?

OBJECTIVES: The aim of the present study was to investigate the prevalence of hypotension in older participants and to identify which 24-hour ambulatory blood pressure monitoring parameter better correlated with the occurrence of hypotension. METHODS: We studied 588 elderly participants (mean age 78.7 ± 7.1 years; 70% women) who underwent a 24-hour ambulatory blood pressure (BP) monitoring, without moderate-to-severe cognitive impairment, myocardial infarction, or stroke within the previous 6 months; renal (serum creatinine > 2.5 mg/dL), respiratory, or liver insufficiency; and atrial fibrillation. RESULTS: In older participants, the occurrence of systolic hypotension is very common (≈55% presenting at least one episode of systolic blood pressure (SBP) < 100 mmHg and about 20% presenting ≥10% of the SBP registrations < 100 mmHg). More than 30% of participants with 24-hour SBP, daytime, and nighttime above the reference threshold had hypotension. Hypotension did not correlated with BP variability indices (standard deviation of BPs). None of the parameters commonly present in 24-hour ambulatory BP monitoring clinical reports is able to accurately identify those older participants with episode of hypotension. CONCLUSION: Episodes of SBP hypotension are extremely common in older participants and do not appear to relate to BP variability indices. Indeed, no parameter of 24-hour ambulatory BP monitoring was capable to accurately identify the occurrence of hypotension. We expect that ongoing studies will contribute to identification of specific factors predicting hypotensive episodes in the older participants.

Plasma osteopontin reveals left ventricular reverse remodelling following cardiac resynchronization therapy in heart failure.

BACKGROUND: Cardiac resynchronization therapy (CRT) promotes left ventricular (LV) reverse remodelling and affects myocardial collagen turnover in heart failure (HF) patients. Osteopontin (OPN) is a matrix glycoprotein required for the activation of fibroblasts upon TGF-ß1 stimulation. In humans, plasma OPN and OPN-expressing lymphocytes correlate with the severity of HF. We sought to evaluate whether plasma OPN and TGF-ß1 reflect LV reverse remodelling following CRT. METHODS: Eighteen patients (12 men, mean age 65 ± 11 years) undergoing CRT were studied. Patients underwent baseline clinical and echocardiographic evaluation, and assessment of plasma OPN and TGF-ß1. The evaluation was repeated 8.5 ± 4 months after device implantation. Eight healthy age- and sex-matched subjects served as controls. RESULTS: In HF patients, baseline plasma OPN and TGF-ß1 were higher as compared to control subjects (OPN: 99 ± 48 vs 59 ± 22 ng/ml; p<0.05; TGF-ß1: 15.9 ± 8.0 vs 9.3 ± 5.6 ng/ml; p<0.05). At follow-up, 12 patients responded to CRT and showed LV reverse remodelling, whereas 6 did not. Plasma OPN decreased in CRT responders (108 ± 47 vs 84 ± 37 ng/ml; p=0.03) and increased in non-responders (79 ± 58 vs 115 ± 63 ng/ml; p<0.01). TGF-ß1 showed a trend towards reduction in responders (17.5 ± 8.7 vs 10.2 ± 8.9 ng/ml; p=0.08) and was unchanged in non-responders. A significant correlation (r=-0.56; p=0.01) was found between relative changes of LVESV and plasma OPN. CONCLUSIONS: CRT-induced LV reverse remodelling is reflected by changes in plasma OPN. Circulating OPN may represent a marker of LV dilation/impairment and an indicator of the response to HF therapies promoting LV reverse remodelling.