Spyridon Katsanos

Left atrial function by two-dimensional speckle-tracking echocardiography in patients with severe organic mitral regurgitation: Association with guidelines-based surgical indication and postoperative (long-term) survival

BACKGROUND Left atrial (LA) mechanics in patients with severe mitral regurgitation (MR) remain largely unexplored. The aim of the present evaluation was to assess the effect of severe MR on LA function, its potential relation with conventional surgical indications, and long-term postoperative survival. METHODS Two-dimensional speckle-tracking strain and volumetric indices of LA reservoir, conduit, and contractile function were assessed in 121 patients with severe MR and 70 controls. Patients were divided according to the presence (n = 46) or absence (n = 75) of one or more guidelines-based criteria for mitral surgery (symptoms, left ventricular ejection fraction ≤ 60%, left ventricular end-systolic diameter ≥ 40 mm, atrial fibrillation, or systolic pulmonary arterial pressure >50 mm Hg). RESULTS In patients with severe MR compared with controls, significant LA reservoir and contractile dysfunction was observed, which was more pronounced in patients with mitral surgery indication (P < .05 for all strain and volumetric indices). Of all indices of LA function, LA reservoir strain was an independent predictor (odds ratio, 0.88; 95% confidence interval, 0.82-0.94; P < .001) and had the highest accuracy to identify patients with indications for mitral surgery (area under the receiver operating characteristic curve, 0.8; 95% confidence interval, 0.72-0.87). A total of 117 patients underwent mitral valve surgery. Patients with LA reservoir strain ≤24% showed worse survival at a median of 6.4 years (interquartile range, 4.7-8.7 years) after mitral surgery (P = .02), regardless the symptomatic status before surgery. LA reservoir strain, on top of mitral surgery indications, provided incremental predictive value for postoperative survival. CONCLUSIONS Impaired LA reservoir strain in patients with severe organic MR relates to long-term survival after mitral valve surgery, independently of and incremental to current guidelines-based indications for mitral surgery.

Subclinical left ventricular dysfunction by echocardiographic speckle-tracking strain analysis relates to outcome in sarcoidosis.

Limited data exist on the risk of developing cardiac sarcoidosis (CS) and/or adverse events in sarcoidosis patients. Using LV global longitudinal strain (GLS), an emerging sensitive parameter of LV function, we evaluated the prevalence of subclinical cardiac dysfunction in sarcoidosis and investigated whether LVGLS predicts adverse outcomes in this population.

Metabolic syndrome is associated with a poor outcome in patients affected by outflow tract premature ventricular contractions treated by catheter ablation

BackgroundThe purpose of this study was to investigate the impact of metabolic syndrome (MS) on outcome of catheter ablation (CA) for treatment of frequent premature ventricular contraction beats (PVCs) originating from right ventricular outflow tract (RVOT), left ventricular outflow tract (LVOT) or coronary cusps (CUSPs), in patients with normal ventricular systolic function and absence of cardiac structural disease.MethodsIn this multicentre prospective study we evaluated 90 patients with frequent PVCs originating from RVOT (n = 68), LVOT (n = 19) or CUSPs (n = 3), treated with CA. According to baseline diagnosis they were divided in patients with MS (n = 24) or without MS (n = 66). The study endpoint was a composite of recurrence of acute or delayed outflow tract ventricular arrhythmia: acute spontaneous or inducible outflow tract ventricular arrhythmia recurrence or recurrence of outflow tract PVCs in holter monitoring at follow up.ResultsPatients with MS compared to patients without MS showed a higher acute post-procedural recurrence of outflow tract PVCs (n = 8, 66.6%, vs. n = 6, 9.0%, p = 0.005). At a mean follow up of 35 (17-43) months survival free of recurrence of outflow tract PVCs was lower in patients with baseline MS compared to patients without MS diagnosis (log-rank test, p < 0.001). In cox regression analysis, only MS was independently associated with study endpoint (HR = 9.655 , 95% CI 3.000-31.0.68 , p < 0.001).ConclusionsMS is associated with a higher recurrence rate of outflow tract PVCs after CA in patients without structural heart disease.

Association between left ventricular global longitudinal strain and adverse left ventricular dilatation after ST-segment-elevation myocardial infarction.

Background—Myocardial infarct size is a major determinant of left ventricular (LV) remodeling after ST-segment–elevation myocardial infarction. We evaluated whether LV global longitudinal strain (GLS), proposed as a novel marker of infarct size, is associated with 3- and 6-month LV dilatation after ST-segment–elevation myocardial infarction. Methods and Results—In the first ST-segment–elevation myocardial infarction patients treated with primary percutaneous coronary intervention, baseline LVGLS was measured with 2-dimensional speckle-tracking echocardiography. Patients were dichotomized according to median value. The independent relationship between GLS groups and LV end-diastolic volume at 3 and 6 months (adjusted for clinical and echocardiographic variables) was assessed. The final study population comprised 1041 patients (60±12 years; 76% men). Median LVGLS was −15.0%. Patients with baseline LVGLS >−15.0% exhibited greater LV dilatation at 3 and 6 months compared with patients with GLS ⩽−15.0% (LV end-diastolic volume 123±44 versus 106±36 mL and 121±43 versus 102±34 mL, respectively; global group–time interaction P<0.001). This association retained the same statistical significance after adjustment for various relevant demographic, clinical, and echocardiographic characteristics. Further, net reclassification improvement index demonstrated significant incremental value of LVGLS for prediction of LV end-diastolic volume increase (0.14 [95% confidence interval, 0.00034–0.29]; P=0.04). Conclusions—LVGLS before discharge after ST-segment–elevation myocardial infarction is independently associated with LV dilatation at follow-up.

Effect of High Doses of Magnesium on Converting Ibutilide to a Safe and More Effective Agent

Ibutilide is a class III antiarrhythmic agent indicated for cardioversion of atrial fibrillation and atrial flutter to sinus rhythm (SR). The most serious complication of ibutilide is torsades de pointes (TdP). Magnesium has been successfully used for the treatment of TdP, but its use as a prophylactic agent for this arrhythmia has not yet been established. The present study investigated whether high dose of magnesium would increase the safety and efficacy of ibutilide administration. A total of 476 patients with atrial fibrillation or atrial flutter who were candidates for conversion to SR were divided into 2 groups. Group A consisted of 229 patients who received ibutilide to convert atrial fibrillation or atrial flutter to SR. Group B consisted of 247 patients who received an intravenous infusion of 5 g of magnesium sulfate for 1 hour followed by the administration of ibutilide. Then, another 5 g of magnesium were infused for 2 additional hours. Of the patients in groups A and B, 154 (67.3%) and 189 (76.5%), respectively, were converted to SR (p = 0.033). Ventricular arrhythmias (sustained, nonsustained ventricular tachycardia, and TdP) occurred significantly more often in group A than in group B (7.4% vs 1.2%, respectively, p = 0.002). TdP developed in 8 patients (3.5%) in group A and in none (0%) in group B (p = 0.009). The administration of magnesium (despite the high doses used) was well tolerated. In conclusion, the administration of high doses of magnesium probably makes ibutilide a much safer agent, and magnesium increased the conversion efficacy of ibutilide.

Tricuspid valve remodelling in functional tricuspid regurgitation: multidetector row computed tomography insights

AIMS Multidetector row computed tomography (MDCT) may help to understand the underlying mechanisms of functional tricuspid regurgitation (TR), a highly prevalent valve disease with novel transcatheter therapies under development. The purpose of the present study was to assess the geometrical changes of the tricuspid valve in patients with functional TR using MDCT and to correlate these changes with the TR grade assessed with echocardiography. METHODS AND RESULTS In 114 patients undergoing transcatheter aortic valve implantation (47 men, age 81 ± 8 years), including 33 (28.9%) patients with TR ≥ 3+, the tricuspid valve and right ventricle (RV) were geometrically analysed with 320-slice MDCT. The antero-posterior and septal-lateral diameters, perimeter and area of the annulus, degree of tethering of the anterior, septal and posterior tricuspid valve leaflets, and RV volumes and ejection fraction were assessed and subsequently correlated with TR grade in multivariate models. Patients with pacemaker or implantable cardioverter defibrillator leads were excluded.Patients with TR ≥ 3+ had larger tricuspid annulus area (1539.7 ± 260.2 vs.1228.4 ± 243.5 mm(2), P < 0.001), larger septal and anterior leaflet angles, and larger RV end-systolic volumes (93.2 ± 29.8 vs. 64.2 ± 23.6 mL, P < 0.001) compared with patients with TR < 3+.The antero-posterior tricuspid annulus diameter was independently correlated with TR ≥ 3+ (odds ratio 1.35; 95% confidence interval 1.07-1.69, P = 0.010), after adjusting for estimated pulmonary pressure and RV end-systolic volume. CONCLUSION In patients with TR ≥ 3+, MDCT demonstrated larger tricuspid annulus and RV dimensions and pronounced tethering of the anterior and septal tricuspid leaflet. The antero-posterior annulus diameter was independently correlated with the grade of functional TR.

Impact of Valvuloarterial Impedance on 2-Year Outcome of Patients Undergoing Transcatheter Aortic Valve Implantation

BACKGROUND Elderly patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI) often have increased calcification and fibrosis of the aorta. Indices that account for the severity of valvular obstruction and systemic vascular impedance may better assess total left ventricular afterload. The aims of the present study were to evaluate changes in valvuloarterial impedance (Zva), systemic arterial compliance, and systemic vascular resistance after TAVI and to investigate the prognostic value of these parameters. METHODS A total of 116 patients (49% men; mean age, 81 ± 8 years) with symptomatic severe aortic stenosis underwent TAVI. Zva, systemic arterial compliance, and systemic vascular resistance were measured at baseline and 1 and 12 months after TAVI. The primary end point was all-cause mortality. RESULTS After TAVI, there was a significant reduction in Zva (from 5.40 ± 1.52 mm Hg/mL/m(2) at baseline to 4.13 ± 1.17 mm Hg/mL/m(2) at 1 month and 4.35 ± 1.38 mm Hg/mL/m(2) at 1 year, P < .001). Systemic arterial compliance (from 0.57 ± 0.27 to 0.57 ± 0.28 and 0.53 ± 0.27 mL/m(2)/mm Hg, P = .408) and systemic vascular resistance (from 1,938 ± 669 to 1,856 ± 888 and 1,871 ± 767, dyne·s·cm(-5), P = .697) did not change significantly over time. During a median follow-up period of 25 months, survival rates of patients with baseline Zva ≥ 5 mm Hg/mL/m(2) were lower compared with those with Zva < 5 mm Hg/mL/m(2) (82% vs 91%, respectively, log-rank P = .04). On multivariate Cox proportional-hazards analysis, baseline Zva was independently associated with all-cause mortality (hazard ratio, 1.48; 95% confidence interval, 1.05-2.07; P = .025). CONCLUSIONS In patients undergoing TAVI, there is a significant postprocedural reduction in Zva, but there is no reduction in systemic arterial compliance or vascular resistance. Baseline Zva is an independent predictor of overall mortality at 2-year follow-up.

Atherosclerosis burden of the aortic valve and aorta and risk of acute kidney injury after transcatheter aortic valve implantation.

BACKGROUND Atheroembolic renal disease, due to dislodgement of cholesterol crystals during maneuvering of a large catheter across the aorta and deployment of the transcatheter prosthesis within a calcified aortic valve, may be one of the pathophysiological mechanisms of acute kidney injury (AKI) complicating transcatheter aortic valve implantation (TAVI). OBJECTIVE To investigate the association between the atherosclerotic burden and plaque characteristics of the aortic valve and thoracic aorta, evaluated with multidetector CT (MDCT), and the occurrence of AKI after TAVI. METHODS Aortic valve calcification, atherosclerosis burden, and plaque characteristics of the thoracic aorta (including aortic root, ascending aorta, aortic arch, and descending aorta) were analyzed in preprocedural MDCT data of 210 TAVI patients (age, 81 ± 7.1 years; 51.4% men). The thoracic aorta was divided into ascending aorta, aortic arch, and descending thoracic aorta which was further divided into 5 to 8 segments according to the posterior intercostal arteries. Each segment where the maximum wall thickness exceeded ≥ 2 mm was defined as diseased segment with atherosclerotic plaque. Aortic atherosclerosis burden was defined as the proportion of thoracic aortic segments with atherosclerosis. AKI was defined by a creatinine level ≥ 1.5 × baseline or ≥ 26.4 μmol/L above baseline. MDCT data were correlated with the occurrence of postprocedural AKI in a multivariate logistic regression model. RESULTS Postprocedural AKI occurred in 51 patients (24.3%). In patients with AKI, the burden of overall (87.5% [75%-90%] vs 71.4% [50%-87.5%]; P < .001) and noncalcified atherosclerosis (42.9% [22.2%-62.5%] vs 12.5% [0%-28.6%]; P < .001) and the maximum plaque thickness (5.7 ± 1.8 mm vs 4.5 ± 1.4 mm; P < .001) were larger compared with patients without AKI. The burden of noncalcified atherosclerosis remained independently associated with AKI (odds ratio, 1.03 [per each 1% of increase in aortic segments with noncalcified atherosclerosis]; 95% confidence interval 1.01-1.05; P = .006) after adjusting for baseline renal function, logistic EuroSCORE, and procedural access. In contrast, aortic valve calcification was not independently associated with AKI. CONCLUSION In patients undergoing TAVI, occurrence of postprocedural AKI was associated with the extent of noncalcified atherosclerotic plaque burden of the thoracic aorta.

Left Ventricular Functional Recovery and Remodeling in Low-Flow Low-Gradient Severe Aortic Stenosis after Transcatheter Aortic Valve Implantation

BACKGROUND Speckle-tracking-derived global longitudinal strain (GLS) is a more sensitive method of detecting left ventricular (LV) functional recovery after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis. However, it remains unknown whether LV function improves in patients with low-flow, low-gradient severe aortic stenosis (LFLGSAS) after TAVI. The aim of the present was to evaluate LV functional recovery and remodeling after TAVI in patients with LFLGSAS. METHODS Sixty-eight patients (57% men; mean age, 79.1 ± 7.1 years) with LFLGSAS treated with TAVI were evaluated. LV function and remodeling were investigated before TAVI and at 6 and 12 months after TAVI. All echocardiographic data were prospectively collected, and GLS was retrospectively analyzed. RESULTS Among patients with LFLGSAS, 35 (52%) had low LV ejection fraction (LVEF) (<50%), and 33 (48%) had preserved LVEF (≥50%). The low-LVEF group had significantly more impaired GLS than the group with preserved LVEF (-8.3 ± 2.6% vs -13.3 ± 3.5%, P < .001). LV systolic function improved after TAVI in both groups. Although in the group of patients with low LVEF, all functional parameters improved, in the group of patients with preserved LVEF, only strain-derived parameters significantly improved. There were significant decreases in absolute LV wall thickness and relative wall thickness and a trend toward decreased LV mass index in both LVEF groups. LV volumes decreased significantly in those with low LVEF but not in those with preserved LVEF. Baseline GLS but not LVEF group was independently associated to GLS improvement at 12 months after TAVI. CONCLUSIONS Patients with LFLGSAS with low and preserved LVEF had a significant improvement in LV function after TAVI, as assessed by GLS. Absolute and relative LV wall thickness decreased in both groups of patients, but only those with low LVEF had reductions in LV volumes.

Quantitative Dobutamine Stress Echocardiography Using Speckle-Tracking Analysis versus Conventional Visual Analysis for Detection of Significant Coronary Artery Disease after ST-Segment Elevation Myocardial Infarction

BACKGROUND Residual ischemia detection after ST-segment elevation myocardial infarction (STEMI) during dobutamine stress echocardiography (DSE) using visual analysis is challenging. The aim of the present study was to investigate the feasibility and accuracy of two-dimensional speckle-tracking strain DSE to detect significant coronary artery disease (CAD) after STEMI. METHODS First STEMI patients (n = 105; mean age, 60 ± 11 years; 86% men) treated with primary percutaneous coronary intervention undergoing full-protocol DSE at 3 months and repeat coronary angiography within 1 year were retrospectively included. Using two-dimensional speckle-tracking echocardiography, segmental and global left ventricular peak longitudinal systolic strain (PLSS) at rest and peak stress and change (Δ) in PLSS were measured. Significant CAD was defined as detection of >70% diameter stenosis at coronary angiography. RESULTS In total, 1,653 (93%) and 1,645 (92%) segments were analyzable at rest and peak stress, respectively. At follow-up, 38 patients (36%) showed significant angiographic CAD. These patients demonstrated greater worsening in global PLSS from rest to peak (-16.8 ± 0.5% to -12.6 ± 0.5%) compared with patients without significant CAD (-16.6 ± 0.4% to -14.3 ± 0.3%; group-stage interaction P < .001). The optimal cutoff of ΔPLSS for the detection of significant CAD on receiver operating characteristic curve analysis was ≥1.9% (area under the curve, 0.70; sensitivity, 87%; specificity, 46%; accuracy, 60%). Using a sentinel segment approach (apex, midposterior, and midinferior for the left anterior descending, left circumflex, and right coronary artery territories, respectively), larger segmental ΔPLSS was also independently associated with significant CAD (odds ratio, 1.1; 95% CI, 1.1-1.2). CONCLUSIONS Two-dimensional speckle-tracking echocardiographic strain analysis is feasible on DSE after STEMI and represents a promising new technique to detect significant angiographic CAD at follow-up.