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Does a Large Left Ventricular Outflow Tract Diameter Influence Calculated Dimensionless Index? Implications for Assessment of Aortic Stenosis Severity
Abstracts
p < 0.01). This difference was most pronounced at the basal level (466 ± 62 ms vs. 566 ± 80 ms, p = 0.02). In HCM patients, the mean T1 time correlated with mean E/e (r = −0.58, p = 0.03). Conclusions: Patients with HCM have shorter myocardial T1 times, consistent with the presence of diffuse myocardial fibrosis. Moreover, the degree of such fibrosis correlates with LV filling pressure, suggesting a mechanistic link between diffuse myocardial fibrosis and abnormal diastolic relaxation in HCM. doi:10.1016/j.hlc.2011.05.423 420 Does a Large Left Ventricular Outflow Tract Diameter Influence Calculated Dimensionless Index? Implications for Assessment of Aortic Stenosis Severity A. Nasis ∗ , S. Moir, S. Lockwood, P. Mottram Monash Cardiovascular Research Centre, MonashHEART and Monash University Department of Medicine (MMC), Melbourne, Australia Background: Grading aortic stenosis (AS) severity is based on assessment of mean aortic valve gradient, calculated aortic valve area (AVA) and dimensionless index (DI, ratio of left ventricular outflow tract [LVOT] velocity time integral [VTI] to aortic valvEVTI). DI < 0.25 is considered to represent severe AS. There is limited available data regarding the influence of LVOT diameter on calculated DI. Methods: 315 consecutive patients were identified with severe AS (mean aortic valve gradient >40 mmHg, AVA < 1 cm2 ) who underwent echocardiography between January 2007 and December 2010. These were divided into patients with large LVOT diameter (≥2.4 cm2 ) and small LVOT diameter (≤2.0 cm2 ). Parameters were compared between groups with a two-tailed unpaired Student’s ttest. Results: There were 32 patients in the large LVOT group and 98 patients in the small LVOT group. Results are summarised in the table below: Male, n (%) Age (years), mean ± SD Body surface area (m2 ), mean ± SD LVOT diameter (cm), mean ± SD AVA (cm2 ), mean ± SD Indexed AVA (cm2 /m2 ), mean ± SD Mean aortic gradient (mmHg), mean ± SD LVOT VTI (cm), mean ± SD Aortic valve VTI (cm), mean ± SD DI, mean ± SD
Large LVOT
Small LVOT
P value
28 (88%) 73.0 ± 11.9 1.94 ± 0.18 2.50 ± 0.10 0.78 ± 0.13 0.40 ± 0.08
21 (21%) 74.3 ± 15.1 1.62 ± 0.35 1.92 ± 0.09 0.62 ± 0.14 0.38 ± 0.09
<0.001 0.65 <0.001 <0.001 <0.001 0.16
55.97 ± 12.17
52.58 ± 10.95
0.14
19.84 ± 3.94 117.91 ± 16.12 0.17 ± 0.03
23.48 ± 5.78 109.93 ± 17.46 0.22 ± 0.05
0.001 0.02 <0.001
Conclusion: Patients with severe AS and large LVOT diameter have lower calculated DI than those with small LVOT diameter. This should be considered when grading AS severity, especially where discrepancy exists between DI, AVA and mean aortic valve gradient. doi:10.1016/j.hlc.2011.05.424
S171
421 Does Increased Valvulo-arterial Impedance Lead to Left Ventricular Hypertrophy and Myocardial Fibrosis in Severe Aortic Stenosis? T. Hall ∗ , L. Huynh, M. Ura, R. Leano, S. Wahi Princess Alexandra Hospital, Australia Background: Valvulo-arterial impedance (Zva) is a composite marker of afterload, combining valvular gradient and arterial compliance and has prognostic significance in aortic stenosis (AS). Increased afterload in AS is associated with raised left ventricular mass index (LVMI) and ultimately myocardial fibrosis. We sought to investigate the relationship between increased Zva and LVMI and fibrosis in myocardial biopsies in AS. Methods: Thirty-eight patients, mean age 69 years (SD = 12.4), 50% females with severe AS underwent preoperative transthoracic echocardiograms (TTE) and intraoperative left ventricular (LV) myocardial biopsies during aortic valve replacement. LVMI and Zva were calculated on TTE (JACC 2005;46:291). Preoperative LV mass index (LVMI) and fibrosis on left ventricular myocardial biopsies were compared with ranges of Zva. Results: Using a Zva cut-off value of 4.5 mmHg/ml/m2 (range 2.4–7.8 mmHg/ml/m2 ) patients were grouped into a high Zva (31.6%, n = 12) or low Zva (68.4%, n = 26) cohort. Mean LVMI in the low and high Zva cohort were 141.6 g/m2 (SD = 6.9) and 148.2 g/m2 (SD = 10.8) respectively, with no significant difference (p = 0.6). The cohort with the low Zva had a lower incidence of myocardial fibrosis 30.7% (n = 8) compared with 58% (n = 7) amongst the high Zva group. Whilst a clear trend of a higher incidence of myocardial fibrosis in patients with higher Zva was noted the difference did not reach statistical significance (p = 0.1). Conclusions: LV hypertrophy did not correlate with high or low Zva. However, a trend towards increased prevalence of myocardial fibrosis in the cohort with higher Zva was found. doi:10.1016/j.hlc.2011.05.425 422 Does Successful TAVI with CoreValve Have a Significant Impact on Cardiac Structure and Function at one Year? S. Lockwood ∗ , I. Meredith, P. Antonis, S. Ciavarella, J. Harley, P. Mottram, S. Moir MonashHeart and Monash Cardiovascular Research Centre, Southern Clinical School, Monash University, Melbourne, Australia Background: Transcatheter Aortic Valve Implantation (TAVI) is an alternative to surgical aortic valve replacement (AVR) for selected patients with severe symptomatic aortic stenosis (SSAS). The long-term effect of TAVI on cardiac structure and function is not clear. We assessed the clinical and echocardiographic outcomes at one year following TAVI with CoreValve (TAVI-C).
ABSTRACTS
Heart, Lung and Circulation 2011;20S:S156–S251
p < 0.01). This difference was most pronounced at the basal level (466 ± 62 ms vs. 566 ± 80 ms, p = 0.02). In HCM patients, the mean T1 time correlated with mean E/e (r = −0.58, p = 0.03). Conclusions: Patients with HCM have shorter myocardial T1 times, consistent with the presence of diffuse myocardial fibrosis. Moreover, the degree of such fibrosis correlates with LV filling pressure, suggesting a mechanistic link between diffuse myocardial fibrosis and abnormal diastolic relaxation in HCM. doi:10.1016/j.hlc.2011.05.423 420 Does a Large Left Ventricular Outflow Tract Diameter Influence Calculated Dimensionless Index? Implications for Assessment of Aortic Stenosis Severity A. Nasis ∗ , S. Moir, S. Lockwood, P. Mottram Monash Cardiovascular Research Centre, MonashHEART and Monash University Department of Medicine (MMC), Melbourne, Australia Background: Grading aortic stenosis (AS) severity is based on assessment of mean aortic valve gradient, calculated aortic valve area (AVA) and dimensionless index (DI, ratio of left ventricular outflow tract [LVOT] velocity time integral [VTI] to aortic valvEVTI). DI < 0.25 is considered to represent severe AS. There is limited available data regarding the influence of LVOT diameter on calculated DI. Methods: 315 consecutive patients were identified with severe AS (mean aortic valve gradient >40 mmHg, AVA < 1 cm2 ) who underwent echocardiography between January 2007 and December 2010. These were divided into patients with large LVOT diameter (≥2.4 cm2 ) and small LVOT diameter (≤2.0 cm2 ). Parameters were compared between groups with a two-tailed unpaired Student’s ttest. Results: There were 32 patients in the large LVOT group and 98 patients in the small LVOT group. Results are summarised in the table below: Male, n (%) Age (years), mean ± SD Body surface area (m2 ), mean ± SD LVOT diameter (cm), mean ± SD AVA (cm2 ), mean ± SD Indexed AVA (cm2 /m2 ), mean ± SD Mean aortic gradient (mmHg), mean ± SD LVOT VTI (cm), mean ± SD Aortic valve VTI (cm), mean ± SD DI, mean ± SD
Large LVOT
Small LVOT
P value
28 (88%) 73.0 ± 11.9 1.94 ± 0.18 2.50 ± 0.10 0.78 ± 0.13 0.40 ± 0.08
21 (21%) 74.3 ± 15.1 1.62 ± 0.35 1.92 ± 0.09 0.62 ± 0.14 0.38 ± 0.09
<0.001 0.65 <0.001 <0.001 <0.001 0.16
55.97 ± 12.17
52.58 ± 10.95
0.14
19.84 ± 3.94 117.91 ± 16.12 0.17 ± 0.03
23.48 ± 5.78 109.93 ± 17.46 0.22 ± 0.05
0.001 0.02 <0.001
Conclusion: Patients with severe AS and large LVOT diameter have lower calculated DI than those with small LVOT diameter. This should be considered when grading AS severity, especially where discrepancy exists between DI, AVA and mean aortic valve gradient. doi:10.1016/j.hlc.2011.05.424
S171
421 Does Increased Valvulo-arterial Impedance Lead to Left Ventricular Hypertrophy and Myocardial Fibrosis in Severe Aortic Stenosis? T. Hall ∗ , L. Huynh, M. Ura, R. Leano, S. Wahi Princess Alexandra Hospital, Australia Background: Valvulo-arterial impedance (Zva) is a composite marker of afterload, combining valvular gradient and arterial compliance and has prognostic significance in aortic stenosis (AS). Increased afterload in AS is associated with raised left ventricular mass index (LVMI) and ultimately myocardial fibrosis. We sought to investigate the relationship between increased Zva and LVMI and fibrosis in myocardial biopsies in AS. Methods: Thirty-eight patients, mean age 69 years (SD = 12.4), 50% females with severe AS underwent preoperative transthoracic echocardiograms (TTE) and intraoperative left ventricular (LV) myocardial biopsies during aortic valve replacement. LVMI and Zva were calculated on TTE (JACC 2005;46:291). Preoperative LV mass index (LVMI) and fibrosis on left ventricular myocardial biopsies were compared with ranges of Zva. Results: Using a Zva cut-off value of 4.5 mmHg/ml/m2 (range 2.4–7.8 mmHg/ml/m2 ) patients were grouped into a high Zva (31.6%, n = 12) or low Zva (68.4%, n = 26) cohort. Mean LVMI in the low and high Zva cohort were 141.6 g/m2 (SD = 6.9) and 148.2 g/m2 (SD = 10.8) respectively, with no significant difference (p = 0.6). The cohort with the low Zva had a lower incidence of myocardial fibrosis 30.7% (n = 8) compared with 58% (n = 7) amongst the high Zva group. Whilst a clear trend of a higher incidence of myocardial fibrosis in patients with higher Zva was noted the difference did not reach statistical significance (p = 0.1). Conclusions: LV hypertrophy did not correlate with high or low Zva. However, a trend towards increased prevalence of myocardial fibrosis in the cohort with higher Zva was found. doi:10.1016/j.hlc.2011.05.425 422 Does Successful TAVI with CoreValve Have a Significant Impact on Cardiac Structure and Function at one Year? S. Lockwood ∗ , I. Meredith, P. Antonis, S. Ciavarella, J. Harley, P. Mottram, S. Moir MonashHeart and Monash Cardiovascular Research Centre, Southern Clinical School, Monash University, Melbourne, Australia Background: Transcatheter Aortic Valve Implantation (TAVI) is an alternative to surgical aortic valve replacement (AVR) for selected patients with severe symptomatic aortic stenosis (SSAS). The long-term effect of TAVI on cardiac structure and function is not clear. We assessed the clinical and echocardiographic outcomes at one year following TAVI with CoreValve (TAVI-C).
ABSTRACTS
Heart, Lung and Circulation 2011;20S:S156–S251