August 29, 2011
Gender Differences In Clinical Presentation And Outcome Of Transcatheter Aortic Valve Implantation
(TAVI) for severe aortic stenosis
Severe aortic stenosis (AS) is increasing in frequency as the population ages. For a subset of patients in whom surgical conventional aortic valve replacement is excluded due to severe co-morbidities, an alternative to surgical aortic valve replacement — transcatheter aortic valve replacement (TAVI)- has emerged with a first-in-man case performed in France in 2002 by Pr. Alain Cribier. Since 2002, TAVI has undergone many modifications from first generation devices, and the technique is now performed routinely in selected centres to treat patients with symptomatic severe aortic stenosis who are ineligible or at high-risk for conventional surgical aortic valve replacement. Two transcatheter heart valves, the "Edwards Sapien valve" and the Medtronic Corevalve" are available in Europe. More than 30,000 procedures have been performed worldwide in the last decade.
Although gender differences in cardiovascular disease (CVD) have been explored for a long time, only a limited number of studies have been conducted to clarify differences between male and female patients with aortic stenosis (AS), in terms of clinical presentation and outcome, after surgical aortic valve replacement (AVR). Certain studies have shown an increased short-term mortality rate among women and the female gender has been identified as one of the predictors of peri-operative mortality after cardiac surgery by EuroSCORE.
The Institut Cardiovasculaire Paris-Sud (ICPS) started a TAVI program in September 2006. In order to address the issue of gender differences in clinical presentation and outcome of TAVI for severe aortic stenosis, clinical characteristics and outcome of 131 women and 129 men treated in ICPS from 2006 to december 2010, were compared. Data were collected prospectively and entered in a dedicated database.
The Edwards valve (85.4%) and Corevalve (14.6%) were used via the transfemoral (65.0%), transapical (31.9%), or subclavian (3.1%) approach. Interestingly, we found that women and men had a similar age at the time of TAVI (83.1ï±6.3 y-o), but women were characterized by less coronary and peripheral disease, less previous cardiac surgery, higher ejection fraction and a lower Euroscore (22.3ï±9.0 vs. 26.2ï±13.0%, p=0.005). Indeed, minimal femoral size (7.74±1.03 vs 8.55±1.34mm, p<0.001), annulus size (20.9±1.4 vs 22.9±1.7mm, p<0.001) and valve size (23.9±1.6 vs 26.3±1.5mm, p<0.001) were smaller in women.
The main results were:
* The rate of TAVI success was similar (p=0.52) between females (90.8%) and males (88.4%) despite increased iliac complication (9.0 vs 2.5%, p=0.03) among female patients.
* One-year survival estimate was higher for women 76% (95%CI, 72-80%) compared to 65% for men (95%CI, 60-69%, log-rank p value =0.022).
* Male gender (HR 1.798: 1.004-3.215, p=0.048) was a strong and independent predictor of one-year mortality after TAVI, along with previous cardiac surgery (HR 2.299: 1.219-4.336, p=0.010), post-procedural aortic regurgitation (HR 2.261: 1.308-3.909, p=0.004), transfusion (HR 2.474: 1.319-4.640, p=0.005), acute kidney injury (HR 6.907: 3.085-15.465, p<0.001), and conversion to surgery (HR 5.147: 1.428-18.550, p=0.012).
CVD has been one of the leading causes of death for decades in our countries, and CVD is the primary cause of death amongst women, killing 8.6 million worldwide every year- more than all forms of cancer combined. Many women remain unaware of the specific risk factors and assume they are less likely to suffer from stroke, heart failure or heart attack. However, evidence shows that this assumption is incorrect, and that there are significant gender differences in both symptoms and disease progression.
The belief that somehow women are protected from cardiovascular disease is wrong and statistics from the World Health Organisation in 2008 actually show that 55% of female deaths in the EU are due to heart attack, stroke and other conditions, compared to 43% of males. Importantly, recent data show that smoking carries a more profound risk for women than men, increasing the heart attack risk by over 50%, and that mortality rates for under-50 females suffering a heart attack are double those for under-50 males, despite programs of coronary artery reopening. Indeed, TAVI outcomes may represent a paradox in the CVD gender gap, with increased rates of survival among females.
In France, the CVD mortality rate decreased from 244/100,000 inhabitants to 172/100,000 inh. between 1950 and 1999 for males, and from 242/100,000 to 178/100,000 for females. Interestingly, a man who has reached 85 years has a 5.81 years life expectancy, whereas an 85 year-old woman can hope to live for 7.35 additional years (Source, French National Institute for Statitstics and Economics, www.insee.fr). The present data suggest that one-year outcome of TAVI is better among women compared to men and evidence shows that the proportion of survivors will still increase among women after years, because of more unfavourable mortality rates in males.
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