Non-invasive electromechanical assessment during atrial fibrillation identifies underlying atrial myopathy alterations with early prognostic value.

Electromechanical characterization during atrial fibrillation (AF) remains a significant gap in the understanding of AF-related atrial myopathy. This study reports mechanistic insights into the electromechanical remodeling process associated with AF progression and further demonstrates its prognostic value in the clinic. In pigs, sequential electromechanical assessment during AF progression shows a progressive decrease in mechanical activity and early dissociation from its electrical counterpart. Atrial tissue samples from animals with AF reveal an abnormal increase in cardiomyocytes death and alterations in calcium handling proteins. High-throughput quantitative proteomics and immunoblotting analyses at different stages of AF progression identify downregulation of contractile proteins and progressive increase in atrial fibrosis. Moreover, advanced optical mapping techniques, applied to whole heart preparations during AF, demonstrate that AF-related remodeling decreases the frequency threshold for dissociation between transmembrane voltage signals and intracellular calcium transients compared to healthy controls. Single cell simulations of human atrial cardiomyocytes also confirm the experimental results. In patients, non-invasive assessment of the atrial electromechanical relationship further demonstrate that atrial electromechanical dissociation is an early prognostic indicator for acute and long-term rhythm control.

The Prevalence of Patient-Prosthesis Mismatch Can Be Reduced Using the Trifecta Aortic Prosthesis.

BACKGROUND: Some important studies have shown that patient-prosthesis mismatch is a frequent occurrence after surgical aortic valve replacement that impairs survival. The Trifecta valve (St. Jude Medical Inc, St. Paul, MN) has special architecture designed to achieve the best hemodynamic profile. The aim of this study was to determine the prevalence of mismatch when using this prosthesis. METHODS: This study included 1,302 patients at 3 months postoperatively, 339 patients with a Trifecta prosthesis and 963 patients (the control group) with a Mitroflow aortic valve (Sorin Group Inc, Mitroflow Division, Vancouver, Canada). Multinomial multivariate logistic regression was calculated to estimate the association between the Trifecta prosthesis and moderate or severe patient-prosthesis mismatch. RESULTS: Any degree of mismatch was present in 5.9% of the Trifecta group and in 42.4% in the Mitroflow group. Moderate patient-prosthesis mismatch was present in 3.8% of the patients with a Trifecta valve and in 32.6% in the Mitroflow group. Severe mismatch was present in 2.1% of the patients with a Trifecta prosthesis and in 9.8% of the patients with a Mitroflow valve. All differences were statistically significant (p < 0.001). The odds ratio of the Trifecta prosthesis as protector against mismatch was 16.9 (95% confidence interval, 9.5 to 30.4) and 11.9 (95% confidence interval, 5.3 to 26.7) for moderate or severe mismatch, respectively. CONCLUSIONS: The prevalence of patient-prosthesis mismatch using the Trifecta aortic prosthesis is extraordinary low. This finding may have great clinical repercussions in patients undergoing surgical aortic valve replacement.

Real Structural Valve Deterioration of the Mitroflow Aortic Prosthesis: Competing Risk Analysis.

INTRODUCTION AND OBJECTIVES: The Mitroflow aortic prosthesis is a bovine pericardial bioprosthesis specially designed to increase the valve area in relation to its size. There is controversy regarding the pattern of structural valve deterioration (SVD). Our aim was to determine the cumulative incidence of SVD, risk factors influencing its occurrence, and its impact on mortality. METHODS: A total of 1028 patients were clinically and echocardiographically followed up. Because the study population was elderly and had heart disease, we used a competing risk analysis. RESULTS: The percentage of patients with SVD at 5 years was 4.22% (95%CI, 2.96-5.81) and was 15.77% at 8 years (95%CI, 12.46-19.43). The incidence was higher for small valves (19mm and 21mm) reaching 6.43% at 5 years (95%CI, 4.48-8.84) and 20.06% at 8 years (95%CI, 15.53-25.01). Severe patient-prosthesis mismatch (PPM) influenced the incidence of SVD (sHR, 3.53; 95%CI, 2.20-5.66; P < .001) but moderate PPM had no impact. The most powerful predictor of mortality was the presence of SVD (HR, 4.59; 95%CI, 2.91-7.22; P < .001). CONCLUSIONS: This study used a definition based on the increase in the transprosthetic gradient and found a higher incidence of SVD of the Mitroflow prosthesis than that reported by other series, especially for sizes 19mm and 21mm and in patients with severe PPM. The incidence of SVD increased exponentially from the fifth year after implantation and its occurrence led to a 4.5-fold increase in the risk of death.

KCNQ1 gene variants in the risk for type 2 diabetes and impaired renal function in the Spanish Renastur cohort.

Several common KCNQ1 gene polymorphisms have been associated with the risk of type 2 diabetes (T2DM) and diabetic nephropathy. This effect is explained by the role of the kcnq1 protein as a potassium channel that in the pancreatic beta-cells drives an electrical signal that facilitates glucose-stimulated insulin secretion. The KCNQ1 gene is also expressed in the kidney, and could thus be implicated in the risk of developing impaired renal function. To test this hypothesis, we genotyped six common KCNQ1 gene variants (three single nucleotide polymorphisms, rs2237892, rs2237895, and rs231362, and three intronic indels) in 681 healthy elderly individuals (>65 years old) from the Spanish Renastur cohort. None of the six variants was associated with T2DM (180 diabetics vs. 581 non-diabetics). The intron 12 insertion allele was associated with a reduced estimated glomerular filtration rate (eGFR<60, n = 90 vs. eGFR≥60, n = 591; II vs ID + DD genotypes, p = 0.031, OR = 2.06, 95%CI = 1.12-4.14). We also performed a next generation sequencing search of variants in the coding regions of the KCNQ1 gene in 100 individuals with the extreme eGFR values. We found two rare amino acid changes (p.K393N and p.P408A) and the 393 Asn variant was found only among diabetics (n = 4; p = 0.05). The two rare alleles were present in the two eGFR groups. Our results suggest that a common KCNQ1 intron 12 indel polymorphism is a risk factor for impaired renal function independent of T2DM. If this association is confirmed by others, further research to determine the mechanism that drives this association would be warranted.

Tomografía computarizada cardiaca: Nuevas aplicaciones de una técnica en evolución / Cardiac computed tomography: New applications of an evolving technique

En los últimos años hemos sido testigos del continuo desarrollo de las técnicas de imagen en cardiología. Entre ellas, la tomografía computarizada cardiaca, técnica emergente y en continua evolución. Con la posibilidad actual de realizar estudios con muy baja radiación se han ampliado sus indicaciones más allá de la coronariografía no invasiva. En el presente trabajo de revisión repasamos las novedades técnicas de la tomografía computarizada cardiaca así como sus nuevas aplicaciones.

During the last years we have witnessed an increasing development of imaging techniques applied in Cardiology. Among them, cardiac computed tomography is an emerging and evolving technique. With the current possibility of very low radiation studies, the applications have expanded and go further coronariography In the present article we review the technical developments of cardiac computed tomography and its new applications.

[Cardiac computed tomography: new applications of an evolving technique]. / Tomografía computarizada cardiaca: Nuevas aplicaciones de una técnica en evolución.

During the last years we have witnessed an increasing development of imaging techniques applied in Cardiology. Among them, cardiac computed tomography is an emerging and evolving technique. With the current possibility of very low radiation studies, the applications have expanded and go further coronariography In the present article we review the technical developments of cardiac computed tomography and its new applications.

Left ventricle non-compaction cardiomyopathy: Different clinical scenarios and magnetic resonance imaging findings / Miocardiopatía no compactada: diferentes escenarios clínicos y hallazgos en cardiorresonancia magnética

Left ventricle non-compaction cardiomyopathy is currently considered as a well-defined individual entity. However, it includes a broad spectrum of clinical, radiological and pathophysiological findings. In this review we describe 3 different scenarios of this entity: an isolated case with severe left ventricle dysfunction, an "associated" case in a patient with previous atrial septum defect and pulmonary stenosis and finally, as a finding in a patient with a transient cerebrovascular ischemic attack. In the 2 last cases, both asymptomatic, morphological criteria of left ventricle non-compaction were found but, ventricular function was normal and cardiac-MRI showed no late gadolinium hyperenhancement. Periodical follow-up and familial screening were recommended. Natural history and prognosis factors of this disease are still not well known. Further and longer series of patients with this diagnosis are needed to completely define radiological criteria, clinical presentation and evolution.

La miocardiopatía no compactada está considerada actualmente como una entidad independiente y bien definida. Sin embargo, presenta un espectro amplio de hallazgos clínicos, radiológicos y fisiopatológicos. En la presente revisión describimos 3 escenarios clínicos diferentes de dicha entidad: un caso con disfunción ventricular severa, un caso como entidad «asociada¼ a una cardiopatía congènita en un pacientes con un defecto del septo interauricular previo y estenosis pulmonar, y finalmente, como un hallazgo casual en un paciente con un accidente cerebrovascular transitorio. En estos 2 últimos casos se encontraron criterios morfológicos de miocardiopatía no compactada con función ventricular normal y sin presencia de realce tardío de gadolinio en el estudio de cardio-RM. En todos ellos se recomendó estudio familiar. La historia natural y el pronóstico de esta anatomía patológica no son todavía del todo conocidos. Series mayores y seguimiento más largos son necesarios para definir completamente los criterios radiológicos, la presentación clínica y la evolución de esta fascinante entidad.

Left ventricle non-compaction cardiomyopathy: different clinical scenarios and magnetic resonance imaging findings.

Left ventricle non-compaction cardiomyopathy is currently considered as a well-defined individual entity. However, it includes a broad spectrum of clinical, radiological and pathophysiological findings. In this review we describe 3 different scenarios of this entity: an isolated case with severe left ventricle dysfunction, an "associated" case in a patient with previous atrial septum defect and pulmonary stenosis and finally, as a finding in a patient with a transient cerebrovascular ischemic attack. In the 2 last cases, both asymptomatic, morphological criteria of left ventricle non-compaction were found but, ventricular function was normal and cardiac-MRI showed no late gadolinium hyperenhancement. Periodical follow-up and familial screening were recommended. Natural history and prognosis factors of this disease are still not well known. Further and longer series of patients with this diagnosis are needed to completely define radiological criteria, clinical presentation and evolution.