Strain como substituto da fração de ejeção

Impact of Longitudinal Myocardial Deformation on the Prognosis of Chronic Heart Failure Patients
Circulation Cardiovascular Imaging. 2010 March 16, 2010
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Methods and Results—The study included 125 consecutive symptomatic HF patients (63±16 years, 77% male, LVEF=31±10%). All patients underwent a complete echocardiographic and clinical examination and brain natriuretic peptide level (BNP) was assessed in 93 patients. Longitudinal myocardial velocity by TDI, global- and SR by speckle tracking were computed from apical views (4-, 3-, and 2-chambers views) and compared to the occurrence of major adverse cardiac events (MACE). On the whole, peak longitudinal velocity, global- and SR averaged 5±2 cm/sec [range, 1-9], -8±3% [range -3 to -18] and -0.33±0.16s-1 [range -0.83 to -0.05], respectively. During the follow-up period (266±177 days), major adverse cardiac events occurred in 47 (38%) patients (15 death, 29 recurrent HF and 4 heart transplantations). By univariable analysis using Cox model global-, SR and LVEF were associated with the occurrence of MACE, while only global- remained independently predictive of outcome by multivariate analysis.

Conclusion—In HF population, longitudinal global strain by speckle tracking is superior to LVEF and other longitudinal markers in identifying patients with poor outcome.
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É um abuso querer superar a fração de ejeção como preditor de eventos. Mas não é que conseguem?
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Somados, podem dar informações importantes, mas separados, só mesmo a deformação longitudinal global medida por speckle tracking foi fortemente preditiva de eventos na alta taxa de quase 40% em 250 dias.
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