Termination of persistent atrial fibrillation (AF) is a valuable ablation endpoint but is difficult to anticipate. We evaluated whether temporal and spatial indices of AF regularization predict ...intraprocedural AF termination and outcome.
The purpose of this study was to test whether temporospatial organization of AF after pulmonary vein isolation (PVI) predicts whether subsequent stepwise ablation will terminate persistent AF or predict outcome.
In 75 patients with persistent AF, we measured AF cycle length (AFCL), temporal regularity index (TRI, a spectral measure of timing regularity), and spatial regularity index (SRI, cycle-to-cycle variations in spatial vector) between right atrial appendage and proximal and distal coronary sinus before and during stepwise ablation to the endpoint of AF termination.
AF termination was achieved in 59 patients (79%) by ablation. AF terminated during PVI in 11 patients, who were excluded from analysis. In the remaining 48 patients, TRI and SRI increased during stepwise ablation, as compared with 16 patients without termination (P<.05). AFCL was prolonged in both groups. From receiver operating characteristics analysis of the first 22 patients (training set), a post-PVI TRI increase predicted AF termination in the latter 42 patients (test set) with a positive predictive value of 96%, negative predictive value of 53%, sensitivity of 71%, and specificity of 91%. Results were similar for SRI. After 36 months, higher arrhythmia-free outcome was observed in patients in whom PVI caused temporospatial regularization in AF.
Temporal and spatial regularization of persistent AF after PVI identifies patients in whom stepwise ablation subsequently terminates AF and prevents recurrence.
The burden of heart failure with preserved ejection fraction (HFpEF) is considerable and is projected to worsen. To date, there are no approved therapies available for reducing mortality or ...hospitalizations for these patients. The pathophysiology of HFpEF is complex and includes alterations in cardiac structure and function, systemic and pulmonary vascular abnormalities, end-organ involvement, and comorbidities. There remain major gaps in our understanding of HFpEF pathophysiology. To facilitate a discussion of how to proceed effectively in future with development of therapies for HFpEF, a meeting was facilitated by the Food and Drug Administration and included representatives from academia, industry, and regulatory agencies. This document summarizes the proceedings from this meeting.
Left ventricular (LV) compliance is an important determinant of LV function and can be affected by a variety of cardiovascular conditions. In particular, diastolic dysfunction is associated with ...altered LV compliance. However, the evaluation of LV compliance is complex. Although the end-diastolic pressure-volume relationship (EDPVR) allows a direct, accurate evaluation of LV compliance, it requires invasive measurements. The aim of this study was to test the feasibility of noninvasive estimation of the EDPVR as a tool to evaluate LV compliance using three-dimensional echocardiography.
Sixty-eight subjects were studied, including 23 normal controls, 22 patients with increased LV compliance due to dilated cardiomyopathy, and 23 patients with reduced LV compliance secondary to isolated diastolic dysfunction as defined using current American Society of Echocardiography guidelines. The EDPVR was calculated for each subject using a nonlinear model with echocardiographic estimates of end-diastolic pressure and volume. For both the isolated diastolic dysfunction and dilated cardiomyopathy groups, predicted end-diastolic volumes at predetermined pressure values (5, 10, 20, and 30 mm Hg) were compared with values in normal controls.
Compared with controls, noninvasive estimates of the EDPVR resulted in predicted end-diastolic volumes that were lower in the isolated diastolic dysfunction group and higher in the dilated cardiomyopathy group (P < .0001 for all four pressure levels). In addition, a stepwise trend of decreased compliance was noted for the different grades of diastolic dysfunction.
This is the first study to demonstrate the feasibility of noninvasive estimation of the LV EDPVR and its ability to differentiate normal from abnormal LV compliance using three-dimensional echocardiography.
Increased Arterial Wave Reflection Magnitude Shah, Sanjiv J., MD; Wasserstrom, J. Andrew, PhD
Journal of the American College of Cardiology,
11/2012, Letnik:
60, Številka:
21
Journal Article
Recenzirano
Odprti dostop
...due to the relatively low number of HF events (though higher than other epidemiological studies 16), the authors could not determine whether their findings differed by sex or race/ethnicity. ......existing and novel cardiovascular therapeutics may reduce the magnitude of wave reflections and subsequently prevent the development of HF; therefore, incorporation of RM into clinical trials should be considered.
" Weighted Numerical Score: 100 - 5 Stars! This is a systematic guide to cardiovascular genetics and genomics from basic concepts to clinical application. It organizes a large volume of information ...from an active area of research, which holds promise for future discovery. --Doody's Reviews Cardiovascular Genetics and Genomics in Clinical Practice presents clinical cases to illuminate basic concepts of cardiovascular genetics and genomics as practitioners encounter them in day-to-day practice. The unique use of real-world case discussions facilitates the memorization and understanding of basic principles, which can be more readily applied to actual cases. Cardiovascular Genetics and Genomics in Clinical Practice features a step-by-step learning process that begins with an easy-to-understand ""primer"" of basic scientific concepts regarding cardiovascular genetics and genomics followed by state-of-the-art research and applications for treatment of cardiovascular disorders. Expert clinicians and researchers describe illustrative cases for each topic along with detailed discussions of current scientific understanding and its application in current disease management and treatment. Summaries, key teaching points, and illustrations are highlighted to facilitate quick recall and review. The book will be useful for cardiovascular clinicians in training, board preparation, or as a review for those already in clinical practice. Cardiovascular Genetics and Genomics in Clinical Practice features: Clinical case scenarios to illuminate the basic concepts of cardiovascular genetics and genomics as they are used in daily practice Explanation of fundamental concepts as a foundation for more in-depth understanding Detailed discussions of current scientific knowledge and clinical management The expertise of renowned clinician-scientists in the field Real practical insight for practice "
Abstract Objectives The purpose of this study was to provide insight into the potential for left atrium (LA) to aortic mechanical circulatory support as a treatment for patients with heart failure ...with preserved ejection fraction (HFpEF). Background Although HFpEF arises from different etiologies, 1 hallmark of all forms of this syndrome is a small or minimally-dilated left ventricle (LV). Consequently, the use of traditional mechanical circulatory support in end-stage patients has been difficult. In contrast, HFpEF is also characterized by a large LA. Methods Hemodynamic characteristics of 4 distinct HFpEF phenotypes were characterized from the published data: 1) hypertrophic cardiomyopathies; 2) infiltrative diseases; 3) nonhypertrophic HFpEF; and 4) HFpEF with common cardiovascular comorbidities (e.g., hypertension). Employing a previously-described cardiovascular simulation, the effects of a low-flow, micropump-based LA decompression device were modeled. The effect of sourcing blood from the LV versus the LA was compared. Results For all HFpEF phenotypes, mechanical circulatory support significantly increased cardiac output, provided a mild increase in blood pressure, and markedly reduced pulmonary and LA pressures. LV sourcing of blood reduced LV end-systolic volume into a range likely to induce suction. With LA sourcing, however, LV end-systolic volume increased compared with baseline. Due to pre-existing LA enlargement, LA volumes remained sufficiently elevated, thus minimizing the risk of suction. Conclusions This theoretical analysis suggests that a strategy involving pumping blood from the LA to the arterial system may provide a viable option for end-stage HFpEF. Special considerations apply to each of the 4 types of HFpEF phenotypes described. Finally, an HFpEF-specific clinical profile scoring system (such as that of INTERMACS Interagency Registry for Mechanically Assisted Circulatory Support) would aid in the selection of patients with the appropriate risk–benefit ratio for implantation of an active pump.
The development of new therapies for heart failure (HF), especially acute HF, has proven to be quite challenging; and therapies evaluated in HF have greatly outnumbered treatments that are eventually ...successful in obtaining regulatory approval. Thus, the development of therapies for HF remains a vexing problem for pharmaceutical and device companies, clinical trialists, and health care professionals. Nowhere is this more apparent than in the phase II HF clinical trial, in which the goal is to determine whether an investigational agent should move forward to a phase III trial. Recent advancements in noninvasive cardiovascular imaging have allowed a new era of comprehensive phenotyping of cardiac structure and function in phase II HF trials. Besides using imaging parameters to predict success of subsequent phase III outcome studies, it is essential to also use imaging in phase II HF trials in a way that increases understanding of drug or device mechanism. Determination of the patients who would benefit most from a particular drug or device could decrease heterogeneity of phase III trial participants and lead to more successful HF clinical trials. In this review, we outline advantages and disadvantages of imaging various aspects of cardiac structure and function that are potential targets for therapy in HF, compare and contrast imaging modalities, provide practical advice for the use of cardiovascular imaging in drug development, and conclude with some novel uses of cardiac imaging in phase II HF trials.
Aortic sclerosis is associated with cardiovascular events in patients without coronary heart disease (CHD), but it is unclear whether this association exists in patients with established CHD or is ...independent of baseline cardiac disease severity. It is also unclear whether statins modify this association. In a prospective cohort study of 814 outpatients with established CHD and no evidence of aortic stenosis, the association of aortic sclerosis with subsequent cardiovascular events was examined using a multivariable Cox proportional hazards model. Of 814 participants, 324 (40%) had aortic sclerosis. During 4 years of follow-up, 10% with aortic sclerosis experienced a myocardial infarction (MI) compared with 5% of those without aortic sclerosis (hazard ratio HR 1.8, 95% confidence interval CI 1.1 to 3.1, p = 0.02). This association was unchanged after adjustment for potential confounders and mediators (HR 2.4, 95% CI 1.3 to 4.8, p = 0.009). However, the association between aortic sclerosis and MI appeared to differ by statin use (p = 0.15 for interaction). Aortic sclerosis predicted subsequent MI in subjects not administered statins (adjusted HR 4.1, 95% CI 1.1 to 15.7, p = 0.04), but not in those administered statins (adjusted HR 1.7, 95% CI 0.8 to 3.9, p = 0.18). In conclusion, aortic sclerosis was present in 40% of patients with CHD and is independently associated with a 2.4-fold increased rate of subsequent MI. Statins may attenuate the increased risk of future MI in patients with aortic sclerosis.
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