Determinants of right ventricular muscle mass in idiopathic dilated cardiomyopathy: impact of left ventricular muscle mass and pulmonary hypertension.

INTRODUCTION: Although chronic pulmonary hypertension and right ventricular (RV) function carry important functional and prognostic implications in idiopathic dilated cardiomyopathy (IDC), little information on RV muscle mass (RVMM) and its determinants has been published. METHODS: Our study comprised thirty-five consecutive patients with IDC, left ventricular (LV) ejection fraction<40% and NYHA class≥2. Hemodynamic data and parameters on LV and RV geometry were derived from right heart catheterisation and cardiac magnetic resonance imaging. RESULTS: RVMM was normalized to body size using a common linear, body surface area based approach (RVMMI) and by an allometric index (RVMM-AI) incorporating adjustment for age, height and weight. Stepwise multiple regression analysis revealed that pulmonary artery pressure and left ventricular muscle mass were independent predictors of RVMM-AI. The interventricular mass ratio of RV and LV mass (IVRM) was closely related to RVMM (r=0.79, p<0.001) and total muscle mass (r=0.39, p<0.02). However, there was no significant relationship between LVMM and IVMR (r=0.17, p=0.32). CONCLUSION: Our data suggest that an increase in RV mass in IDC may be explained by two mechanisms: First, as a consequence of the myopathic process itself resulting in a balanced hypertrophy of both ventricles. Second, due to the chamber specific burden of pulmonary artery pressure rise, resulting in unbalanced RV hypertrophy.

Utility of Coronary Computed Tomography Angiography in Patients Undergoing Transcatheter Aortic Valve Implantation: A Meta-Analysis and Meta-Regression Based on Published Data from 7458 Patients.

BACKGROUND: Coronary CT angiography (CCTA) may detect coronary artery disease (CAD) in transcatheter aortic valve implantation (TAVI) patients and may obviate invasive coronary angiography (ICA) in selected patients. We assessed the diagnostic accuracy of CCTA for detecting CAD in TAVI patients based on published data. METHODS: Meta-analysis and meta-regression were performed based on a comprehensive electronic search, including relevant studies assessing the diagnostic accuracy of CCTA in the setting of TAVI patients compared to ICA. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated on a patient and per segment level. RESULTS: Overall, 27 studies (total of 7458 patients) were included. On the patient level, the CCTA's pooled sensitivity and NPV were 95% (95% CI: 93-97%) and 97% (95% CI: 95-98%), respectively, while the specificity and PPV were at 73% (95% CI: 62-82%) and 64% (95% CI: 57-71%), respectively. On the segmental coronary vessel level, the sensitivity and NPV were 90% (95% CI: 79-96%) and 98% (95% CI: 97-99%). CONCLUSIONS: This meta-analysis highlights CCTA's potential as a first-line diagnostic tool although its limited PPV and specificity may pose challenges when interpreting heavily calcified arteries. This study underscores the need for further research and protocol standardization in this area.

Effects of exercise on the duration of diastole and on interventricular phase differences in patients with hypertrophic cardiomyopathy: relationship to cardiac output reserve.

BACKGROUND: Our study sought to characterize the effect of exercise on the duration of left ventricular (LV) diastole and interventricular dyssynchrony in patients with hypertrophic cardiomyopathy (HCM). We hypothesized that an abnormally shortened diastolic time may adversely affect cardiac performance. METHODS: We studied 49 symptomatic patients with HCM during incremental exercise. Twenty-nine patients had obstructive disease (HOCM) and 20 no resting or provocable gradient (HNCM). Right heart catheterization and high temporal resolution radionuclide angiography were simultaneously performed. The loss of diastolic time per beat (LDT(RR)) was quantified using a regression equation obtained from a healthy control group (n = 30). RESULTS: During rest and peak exercise, a significant shortening of the relative duration of LV diastole (35.6 +/- 5 vs. 38.0 +/- 3 s/min and 29.3 +/- 6 vs. 32.4 +/- 3 s/min; P < or = .02) and an increased interventricular phase delay were evident in patients with HOCM compared to controls. Baseline and peak exercise LDT(RR) values were inversely related to cardiac output reserve and exercise duration. In multivariate analysis, LDT(RR) at peak exercise was identified as an independent predictor of cardiac output reserve. CONCLUSIONS: In HOCM, baseline abnormalities of the relative duration of LV systolic and diastolic time aggravate during exercise. The disproportionate shortening of diastolic time may significantly impair cardiac efficiency by restricting diastolic filling.

Disproportionate shortening of diastolic time and cardiac performance in asymptomatic patients with aortic regurgitation.

BACKGROUND AND AIM OF THE STUDY: Exercise-induced abnormalities of the systolic-diastolic phase proportion and their impact on hemodynamic variables have been investigated only minimally in asymptomatic patients with chronic aortic regurgitation (AR). METHODS: A group of 33 asymptomatic patients with severe AR and preserved left ventricular (LV) systolic function was studied during incremental exercise, using a combined hemodynamic-radionuclide angiographic approach. The phases of the cardiac cycle were derived with high temporal resolution from the LV time-activity curve. The loss of diastolic time per beat (LDT) was quantified using a regression equation obtained from a healthy control group (n=26). Based on the median LDT at peak exercise, patients were allocated to two groups with LDT < or = 12.4 ms (group A) and LDT > 12.4 ms (group B). RESULTS: At peak exercise the relative duration of LV diastole was significantly shorter in AR patients than in controls (31.4 +/- 3.0 versus 33.1 +/- 2.4 s/min; p = 0.02) and a significant LDT (12.1 +/- 19 ms; p = 0.003) was observed. Group A patients had a higher peak cardiac output (9.2 +/- 2.0 versus 7.4 +/- 2 l/min/m2; p < 0.03), a longer exercise duration (18 +/- 5 min versus 13 +/- 6 min; p < 0.02) and a lesser extent of mean pulmonary artery pressure rise (27 +/- 10 versus 34 +/- 12 mmHg; p = 0.03) than group B patients. CONCLUSION: Cardiac exercise performance in asymptomatic patients with AR is influenced not only by the ability of the cardiovascular system to favorably redistribute total stroke volume, but also to handle volume overload without changing the systole and diastole phase proportions.

Masked diastolic dysfunction caused by exercise testing in hypertensive heart failure patients with normal ejection fraction and normal or mildly increased LV mass.

INTRODUCTION: It is not clear whether in patients with the clinical suspicion of heart failure with normal ejection fraction (HFNEF) exercise assessment of diastolic function may help to unmask abnormalities not detected by resting measurements. METHODS AND RESULTS: A combined radionuclide angiographic and haemodynamic exercise study was performed to confirm definite diastolic dysfunction in hypertensive patients with exertional dyspnoea and no other detectable cause of their symptoms. Only patients with normal baseline left ventricular (LV) systolic and diastolic function parameters as evaluated by routine cardiac catheterization and transmitral Doppler echocardiography were accepted (n = 38). All parameters were compared to a control group (n = 10). Twenty-eight patients showed an abnormal elevation in pulmonary capillary wedge pressure with exercise. As a consequence of a reduced exercise stroke volume (58 +/- 13 vs. 70 +/- 12 ml/m2; P = 0.01) peak cardiac output was reduced in HFNEF (9.3 +/- 1.7 vs. 7.6 +/- 2.0 l/min/m2; P = 0.02). These changes were equally demonstrable in patients with and without ventricular hypertrophy. LV end-systolic wall stress (ESWS) was increased at rest and during exercise in HFNEF patients without hypertrophy. However, a positive relationship between ESWS and the corresponding exercise stroke volume (r = 0.57; P = 0.002) was observed in the entire HFNEF group. CONCLUSION: Detection of diastolic dysfunction in suspected HFNEF is not only a question of the diagnostic methods used, but of the conditions under which the patients are investigated.

Loss of diastolic time as a mechanism of exercise-induced diastolic dysfunction in dilated cardiomyopathy.

BACKGROUND: Cardiac performance can be characterized in terms of the relative duration of left ventricular systole and diastole. Little is known about exercise-induced abnormalities of the systolic-diastolic phase proportion and its impact on hemodynamic variables in patients with idiopathic dilated cardiomyopathy (IDCM). METHODS: The phases of the cardiac cycle were derived with high temporal resolution from the left ventricular time-activity curve simultaneous with hemodynamic measurements. In patients with IDCM, the loss of diastolic time (LDT) per beat was quantified using a regression equation obtained from a healthy control group (n = 26). According to the median LDT at peak exercise, patients were divided into 2 subgroups: subgroup A with an LDT 22 milliseconds (n = 27). RESULTS: The relative duration of left ventricular systole was increased in patients with IDCM during peak exercise compared to healthy subjects (29.3 vs 26.7 s/min, P < .02). This abnormality translated into a significant LDT when observed, and predicted values of diastolic time were compared. Subgroup B patients had a higher increment in mean pulmonary capillary wedge pressure but a smaller increase in stroke volume index from rest to peak exercise (14.3 vs 8.6 mm Hg [P = .007] and 12.5 vs 7.2 mL/m(2) [P = .04]) compared to subgroup A patients. CONCLUSION: An abnormal shortening of diastolic time during exercise can restrict left ventricular filling to an extent that is sufficient to limit left ventricular stroke volume reserve and to cause pulmonary congestion.

Different effect of exercise on left ventricular diastolic time and interventricular dyssynchrony in heart failure patients with and without left bundle branch block.

BACKGROUND: In patients with idiopathic dilated cardiomyopathy (IDCM) a prolongation of left ventricular (LV) systole at the expense of diastolic time was demonstrated. Our study was aimed to evaluate the effect of exercise on heart rate corrected diastolic time in controls, IDCM with and without LBBB, and patients with LBBB and normal LV function. METHODS: 47 patients with IDCM, 30 without LBBB, and 17 with LBBB as well as 11 with isolated LBBB were studied during exercise using a combined hemodynamic-radionuclide angiographic approach. The phases of the cardiac cycle were derived with high temporal resolution from the ventricular time-activity curve. The loss of diastolic time per beat (LDT) was quantified using a regression equation obtained from a control group (n=24). RESULTS: A significant LDT was demonstrated at rest and during peak exercise in IDCM patients with LBBB (39.1+/-32 and 37.3+/-30 ms; p < 0.001). In IDCM patients with normal activation LDT was unaffected at baseline, but elevated during peak exercise. This response was paralleled by an increase in interventricular mechanical dyssynchrony. CONCLUSION: During exercise an abnormal shortening of LV diastolic time is a common characteristic of heart failure patients which can be explained by the high prevalence of mechanical dyssynchrony.

Delayed pacemaker requirement after transcatheter aortic valve implantation with a new-generation balloon expandable valve: Should we monitor longer?

OBJECTIVES: To analyze the timing of appearance of conduction abnormalities (CAs) after transcatheter aortic valve implantation (TAVI), to identify predictors of delayed CAs requiring pacemaker (PM) implantation and to provide guidance regarding the duration of telemetry monitoring. BACKGROUND: How long patients remain at risk of development of CAs requiring PM implantation after TAVI and for how long they should be monitored remains unclear but is crucial when considering early discharge. METHODS: Development of CAs was studied in 701 consecutive patients treated with Edwards Sapien 3 valves and monitored with telemetry for 7 days in a single center. After excluding valve-in-valve procedures and patients with previous PM, 606 patients remained for analysis. Predictors of CAs requiring PM and the time of onset of CAs were analyzed. RESULTS: Of 606 patients 76 (12.5%) required a PM after TAVI. CAs requiring PM implantation occurred after 48 h in 22.4% (17 patients) and in 10.5% (8 patients) even after 5 days. Of the patients who developed high grade CAs requiring PM after 48 h, 47.1% had no CAs prior to TAVI, and 23.5% had neither pre-existing CAs nor new-developed CAs within the first 48 h after TAVI. CONCLUSION: After TAVI using a new-generation balloon-expandable valve, delayed development of CAs requiring PM implantation is not uncommon, even after 5 days. More importantly, 23.5% of patients eventually requiring a delayed PM implantation had still no CAs at 48 h after TAVI in this study. These results question the safety of early discharge and support ECG monitoring for a longer time period. The most optimal way to monitor these patients is yet to be determined.

Prevention of sudden cardiac death in patients with Tetralogy of Fallot: Risk assessment and long term outcome.

BACKGROUND: In patients with repaired Tetralogy of Fallot (ToF), implantable cardioverter defibrillators (ICD) are considered reasonable in selected adults with multiple risk factors for sudden cardiac death. PATIENTS AND METHODS: We performed a retrospective cohort study of all 174 patients with repaired ToF who are followed at the University Hospital of Muenster. We analyzed data according to the risk score previously proposed by Khairy and coworkers and patient outcome. We analyzed data separately for patients without previous sustained ventricular tachycardia (VT) (risk stratification group, n = 157) and patients with VT/secondary prevention ICD (n = 17). RESULTS: In the risk stratification group, a mean of 4 ±â€¯1 risk score parameters were available. All six risk parameters were known in 10%, five in 14%. Risk score increased with availability of parameters. 15 patients with secondary prevention ICD had a mean risk score of 6.3 ±â€¯2.2 (range 2-10). 11 patients of the risk stratification group with primary prevention ICD had a mean risk score 5.8 ±â€¯2.4 (range 3-8). During follow-up of up to 14 years, five patients died (3%): at age 58, two at 69 and two at 76 years. CONCLUSION: In the majority of patients risk score variables were incomplete, severely limiting its applicability because the true score cannot be calculated. Risk scores were not different between patients with secondary prevention ICD and patients with ICD for primary prevention based on current guidelines. Standardization of follow-up and prospective evaluation of these standards in large prospective patient cohorts is desirable to improve risk stratification in patients with ToF.

[Disproportionate shortening of left ventricular diastolic duration in patients with dilated cardiomyopathy]. / Abnorme Verkürzung der linksventrikulären Diastolendauer unter körperlicher Belastung bei Patienten mit dilatativer Kardiomyopathie.

BACKGROUND AND PURPOSE: Cardiac performance can be characterized in terms of the relative duration of systole and diastole. In pediatric patients with dilated cardiomyopathy (DCM), a disproportionate shortening of left ventricular diastole was observed. The present study was intended to reproduce these findings in an adult patient group and to evaluate exercise-related changes of both time intervals. PATIENTS AND METHODS: Exercise radionuclide angiography was used in 61 patients with DCM NYHA (New York Heart Association) stage II-III. The phases of the cardiac cycle were derived from a radionuclide time-activity curve with high temporal resolution. The control group consisted of 26 patients referred for ventricular function assessment with radionuclide angiography before cardiotoxic cancer treatment. RESULTS: When the duration of systole was expressed as the product of systolic time and heart rate, DCM patients exhibited a significant increase in left ventricular systolic time at rest (23.9 vs. 21.5 s/min; p = 0.006) and during peak exercise (29.2 vs. 26.7 s/min; p = 0.01). The prolongation of left ventricular systole at peak exercise was evident, although the peak heart rate was significantly lower in the patient group than in the control group (118 vs. 127/min; p = 0.04). In DCM patients the diastolic time loss per beat was further quantified using a regression equation obtained from the healthy control group. A significant shortening of left ventricular diastolic time was confirmed during peak exercise. Furthermore, a progressive loss in diastolic time per beat from rest to peak exercise was noted. CONCLUSION: Cardiac cycle abnormalities of patients with DCM are characterized by a prolongation of left ventricular systole and an abnormal shortening of left ventricular diastole. The systolic-diastolic mismatch is accentuated during exercise and has the potential to impair the cardiac reserve in these patients by restricting ventricular filling and perfusion.

Changes in the Pacemaker Rate After Transition From Edwards SAPIEN XT to SAPIEN 3 Transcatheter Aortic Valve Implantation: The Critical Role of Valve Implantation Height.

OBJECTIVES: The aim of this study was to analyze the pacemaker implantation rate (PMIR) with the new balloon-expandable Edwards SAPIEN 3 valve (S3) and the factors associated with it. BACKGROUND: The introduction of the S3 for transcatheter aortic valve replacement (TAVR) has led to a reduction in paravalvular regurgitation. There are, however, concerns that the new design may increase the PMIR. METHODS: The first 206 patients treated with the S3 were compared with 371 preceding patients treated with SAPIEN XT valves. Patients who previously underwent pacemaker or implantable cardioverter defibrillator implantation or transapical and valve-in-valve procedures were excluded from the analysis. All patients were monitored for at least 7 days. Previous and new conduction abnormalities were documented, and prosthesis implantation height was assessed for the S3. RESULTS: There were no significant differences in baseline characteristics between groups. The PMIR was, however, significantly higher for the S3 (19.1% vs. 12.2%; p = 0.046). The mean implantation height was significantly lower in patients requiring PMI (67%/33% vs. 72%/28% aortic/ventricular stent extension, p = 0.032). On multivariate regression analysis, implantation height was the only independent predictor of PMI (odds ratio: 0.94 [95% confidence interval: 0.90 to 0.99]; p = 0.009). It increased from 68%/32% to 75%/25% when comparing the first with the second half of S3 implantations (p < 0.0001). This change was associated with a significant decrease in PMIR from 25.9% to 12.3% (p = 0.028), no longer different from the XT valve (12.2%). CONCLUSIONS: The PMIR after TAVR is higher with the S3 than with the XT and is independently associated with the implantation height. This increase in the PMIR may be avoided by intending an aortic stent extension >70%.

Transradial versus transfemoral approach in coronary angiography: a matched pair analysis of cath lab equipment costs.

INTRODUCTION: There is an ongoing struggle to understand the potential economic benefits that radial access may offer. Cost savings are thought to primarily occur after the procedure. The aim of our study was to analyze cath lab expenses resulting from transradial (TRA) and transfemoral approaches (TFA). METHODS: A total of n = 1890 matched pairs of patients were analyzed. A traditional Judkins catheter strategy was pursued for coronary angiography. Three large databases were merged to collect and compare procedural data as material, medication costs and fluoroscopy time. RESULTS: Compared to TFA diagnostic catheterization from TRA was associated with significantly lower procedural costs (€181.0 versus €167.5; p<0.001). Extra costs in TFA were primarily produced by frequent use of vascular closure devices (VCDs) in 86% of patients. However, the potential saving amount related to VCD use was only partly realized due to the higher number of extra catheters (0.53 ± 0.9 versus 0.23 ± 0.6; p<0.001) and hydrophilic guidewires (0.088 ± 0.3 versus 0.014 ± 0.1; p<0.001) used in TRA. Weak correlations were observed between the total number of cases and fluoroscopy time (r = -0.13; p<0.001) as well as material costs (r = 0.31; p<0.001). CONCLUSIONS: Significant cost savings can be realized by TRA at the procedural level even when adhering to a conventional Judkins catheter strategy. Hydrophilic guidewires and additional catheters are the main cost drivers in TRA. In contrast to fluoroscopy time material costs steadily increase during the early stage of the TRA learning curve.

Comparison of right ventricular functional response to exercise in hypertrophic versus idiopathic dilated cardiomyopathy.

Although the biventricular nature of the disease has been confirmed by morphologic studies, information on right ventricular (RV) function in hypertrophic cardiomyopathy (HC) is lacking. The aim of the study was to hemodynamically characterize RV performance in HC versus idiopathic dilated cardiomyopathy (IDC) during exercise. The hemodynamic data of 63 patients with HC who underwent hemodynamic exercise testing with thermodilution-derived assessment of RV ejection fraction were analyzed. The results were compared to a healthy control group (n = 20) and to patients with IDC (n = 86). The baseline RV ejection fraction was increased in the patients with HC compared to those with IDC (39 +/- 10% vs 33 +/- 12%; p = 0.002), but did not differ compared to controls (42 +/- 7% vs 39 +/- 10%; p = NS). An increase in end-diastolic volume from rest to exercise contributed to stroke volume augmentation in those with HC (121 +/- 38 vs 136 +/- 55 ml/m(2); p = 0.01) and control subjects (116 +/- 34 vs 138 +/- 31 ml/m(2); p = 0.002) but not in those with IDC (117 +/- 47 vs 120 +/- 52 ml/m(2); p = NS). At peak exercise the RV ejection fraction in those with HC was reduced compared to that in the controls (45 +/- 11% vs 59% +/- 9%; p <0.001), but it was increased compared to that in those with IDC (45 +/- 11% vs 35% +/- 11%; p <0.001). In conclusion, the extent of the pulmonary pressure increase was more pronounced in those with HC than in those with IDC, but the degree of functional impairment of the right ventricle was less severe, probably owing to its ability to recruit preload and contractile reserve with exercise.

Prevalence of ventricular discordance and its relation to functional capacity in idiopathic dilated cardiomyopathy.

INTRODUCTION: Although left ventricular (LV) dilatation is the most distinguishing morphologic feature of idiopathic dilated cardiomyopathy (IDC), right ventricular (RV) dilatation may variably contribute to total cardiac enlargement. The prevalence and functional importance of the relative degree of left and right ventricular dilatation has not been comprehensively studied using cardiac magnetic resonance imaging (MRI). METHODS: Our prospective study included 58 consecutive IDC patients with a LV ejection fraction <40% and NYHA functional class > or =2. MRI was performed with a 1.5 Tesla scanner for RV and LV dimensional and functional analysis. Cardiopulmonary exercise testing was used for evaluation of exercise capacity. Patients were grouped into tertiles based on the distribution of LV end-diastolic volume. RESULTS: Compared to control subjects a considerable heterogeneity in the relative degree of left and right ventricular dilatation was noted in IDC patients. Within the entire patient group, a strong correlation between the degree of ventricular volume discordance and the extent of LV enlargement was observed (r = 0.8; P < 0.001). Tertile analysis revealed that the LV/RV volume ratio significantly differed in the three subgroups of patients (1.0 +/- 0.3 vs. 1.5 +/- 0.4 vs. 2.1 +/- 0.9; P < 0.001). Only weak correlations between MRI data and patients' functional capacity were found. LV ejection fraction was identified as the only independent predictor of maximum oxygen consumption in our setting. CONCLUSION: In IDC patients the degree of ventricular volume discordance is strongly related to the extent of left ventricular enlargement. However, comprehensive biventricular assessment of cardiac function by MRI adds little to our understanding of the cardiac mechanisms limiting exercise tolerance when compared to exclusive left ventricular measurements.