Impaired physical quality of life in patients with diastolic dysfunction associates more strongly with neurohumoral activation than with echocardiographic parameters: Quality of life in diastolic dysfunction.
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American Heart Journal
Issue: Volume 161(4), April 2011, p 797–804
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In DIAST-CHF, DD was prospectively identified and graded by an algorithm defined in the study protocol: Normal diastolic function (1 <= E/A, E/e' <10, S/D >=1, E/A with Valsalva maneuver >=1), mild DD (E/A <1), moderate DD (1 <= E/A <2 and 1 of the following: E/e' >=10, S/D <1, E/A Valsalva <1), and severe DD (E/A >=2 and 1 of the following: E/e' >=10, S/D <1). . Conclusions: Physical dimensions of Quality of life are reduced in DD. Impaired Short Form 36-PF is only weakly associated with DD per se but rather seems to be contingent on the presence of elevated filling pressures. Biomarkers are more strongly and independently associated with SF-36-PF and may be more adequate surrogate markers of QoL in DD than echocardiographic measurements.
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Marcadores de disfunção diastólica ao ecocardiograma se correlacionam fracamente com índices obtidos por um questionário de qualidade de vida.
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O que será que estamos medindo ao ecocardiograma que não se correlaciona com a qualidade de vida, com o tratamento e mesmo com a redução da mortalidade?!?!?!?!?!?
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Preserved exercise capacity in HF may be due to better diastolic function
ResponderExcluirMontreal, QC - Among patients with heart failure and very low LV ejection fraction, having better diastolic function—an E/e' ratio lower than 10.8—predicted preserved exercise capacity, a new study found [1]. Dr Takahiro Ohara (Wake Forest University, Winston-Salem, NC) presented the study here at the American Society of Echocardiography (ASE) 2011 Scientific Sessions.
In their clinical practice, they noted that some patients with very low ejection fractions still had a remarkable ability to exercise, Ohara told heartwire. The team hypothesized that although lifestyle factors may be playing a role, part of the explanation for this difference in exercise capacity was likely due to differences in diastolic function.
Their results, in a population of patients who underwent stress echo, show that better diastolic function "is not the whole explanation of normal exercise capacity, but it is one of the essential parts of normal exercise capacity," he said.
Commenting on this study, Dr Brad Munt (St Paul's Hospital, Vancouver, BC) said: "From a clinical standpoint, physicians can now look at the E/e' ratio in their patients with a low ejection fraction, and if it is high (>11.75, this study suggests) conclude that diastolic dysfunction is contributing to the exercise intolerance." Further studies will be needed to elucidate what other factors may be involved and determine optimal therapy, he added, noting that previous work has suggested that right ventricular function and peripheral muscle adaptations may be contributing factors.
Why are some impaired patients more mobile?
A cardinal symptom of heart failure is exercise intolerance, and in heart failure with a low ejection fraction, ejection fraction and exercise capacity are independent predictors of mortality, Munt noted. It has been assumed that the reduced exercise capacity was due to the low ejection fraction; however, physicians have noted that some people with low ejection fractions have preserved exercise capacity, he added.
To investigate their hypothesized link between diastolic function and exercise capacity, Ohara and colleagues analyzed results from consecutive patients with significant LV dysfunction (LVEF <35%) who underwent stress echocardiography in their center from 2006 to 2010 and who did not have exercise-induced ischemia.
The study population included 125 patients (85% men) with a mean age of 60+12 years and a mean ejection fraction of 25%+6%. The team divided the patients into two groups:
•Preserved exercise tolerance (n=33)—Patients with an exercise duration >100% of that expected for their age and gender.
•Impaired exercise tolerance (n=92)—Patients with an exercise duration <100% of that expected for their age and gender.
Trans-mitral Doppler showed that patients with preserved exercise tolerance had significantly lower E-wave velocity and a longer deceleration time, which is related to relaxation of the myocardium, said Ohara. Tissue Doppler imaging showed that s' (a measure of systolic function) and e' (a measure of diastolic function) were similar.
ResponderExcluirBased on variables determined by trans-mitral Doppler and tissue Doppler imaging, the patients' diastolic dysfunction was graded according to American Society of Echocardiography/European Association of Echocardiography (ASE/EAE) guidelines as normal, grade I, grade II, or grade III. About half of the patients in the impaired-exercise group had the worst level of diastolic function (grade III), whereas this was true for only about 19% of patients in the preserved-exercise group.
Multiple logistic regression analysis adjusted for age and sex showed that preserved exercise tolerance was predicted by E/e' (odds ratio 0.86, 95% CI 0.77-0.97; p=0.01) and by deceleration time (OR 1.01, 95% CI 1.00-1.02; p=0.03).
A receiver operating characteristics (ROC) analysis showed that E/e' <10.8 detected normal exercise tolerance with a sensitivity of 70% and a specificity of 69%.
Greater focus on diastolic issues needed
"This was a well-done study that shows that a measure of diastolic function, E/e' ratio, is a modest and deceleration time a weak predictor of exercise capacity," Munt commented. The ROC analysis shows that other factors not identified in this study are also responsible, he noted.
Further study is needed to identify other contributing factors, to find ways to improve diastolic dysfunction, and to find specific medications that target this dysfunction in patients with reduced LV ejection fraction, Ohara said. "Further research should focus on diastolic dysfunction, not only for prognosis but also to improve exercise capacity and quality-of-life issues," he concluded.