Page 67 - The role of advanced echocardiography in patients with ischemic heart disease - Rachid Abou

longer PWD values (43±12 ms) than previous studies,17, 18 but this may be related to a larger proportion of individuals aged >75 years (17%) in the current study (13% in the Framingham Heart Study while the meta-analysis included age categories up to 45 years of age).18
Several studies have shown the age-dependency of PA-TDI duration.19, 20 Erdem et al. 3 demonstrated in 80 healthy subjects aged between 20 and 40 years that the PA-TDI
duration increased with older age (β=0.342, p=0.001).19 Weijs et al.20 evaluated the
correlates of PA-TDI in 427 patients, and reported a mean PA-TDI duration of 157±22
ms, while age was independently associated with increasing PA-TDI on multivariable analysis (each 10 years increase in age was associated with 5 ms increase in PA-TDI). The study by Weijs et al. however, included a broad spectrum of patients (with history of atrial fibrillation, heart failure and valvular heart disease), and therefore the PA-TDI values do reflect more than just the effect of ageing.
Finally, the association between ageing and changes in LA reservoir strain has been demonstrated in previous studies.3,5,21,22 In 188 healthy individuals (21-80 years; 43% male) free of cardiovascular disease or cardiovascular risk factors, Boyd et al showed that TDI-derived global longitudinal strain of the LA (representing reservoir function) was independently associated with age.21 Interestingly, the reduction in LA reservoir strain was apparent from the sixth decade whereas LA dilatation was observed from the seventh decade suggesting that LA strain measures may be more sensitive of structural LA changes than conventional echocardiographic parameters. In the present study, there were no significant changes in LA volume and LV mass. However, we did observe a higher prevalence of diastolic dysfunction with increasing age. The association between age and LA reservoir strain was modulated by LA volume suggesting that diastolic dysfunction leads to dilatation of the LA and therefore the influence of age on LA reservoir strain is reduced. In addition, the present study demonstrated that LA reservoir strain is independently associated with BMI. In overweight and obese patients, it has been demonstrated that the increase of epicardial fat tissue is associated with increased LA dimensions and reduced LA compliance.23 In 70 patients (including 50% obese patients, with BMI ≥ 30 Kg/m2), Erdem et al. showed that LA reservoir strain was significantly more reduced in obese patients as compared to their counterparts (33.1±8.8% vs. 46.2±8.9%, p<0.001, respectively).24
Several limitations should be acknowledged. The current study was retrospective in nature and did not include “healthy” individuals since a significant proportion had cardiovascular risk factors or used cardiovascular medication that may influence LA
61