Criteria predicting response to CRT: is more better?
Criteria predicting response to CRT: is more better?
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预测 CRT 反应的标准：越多越好吗？
DOI：
10.1093/eurheartj/ehp378
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发表时间：
2009
影响因子：
39.3
通讯作者：
Abraham,TheodoreP
中科院分区：
文献类型：
--
作者：
Santaularia-Tomas,Miguel;Abraham,TheodoreP
The quest for the perfect parameter to predict response to cardiac resynchronization therapy (CRT) suffered a major setback when two prospective trials (PROSPECT and ReTHINQ) demonstrated limitations in the potential clinical value of the much-touted tissue Doppler velocity-based criteria. 1, 2 Until then there was a steady stream of ‘highly accurate’predictors of response to CRT. 3–5 Notwithstanding the bevy of potential technical issues plaguing these studies, they did successfully raise serious doubts about how the clinical community and vendors were going about identifying patients likely to respond to CRT. We have always been of the opinion that attempting to solve a complex issue such as predicting response to CRT by means of a single binary parameter, such as tissue Doppler velocity-derived delays, is overly simplistic. For what it is worth, several studies over thousands of patients do indicate some value to testing dyssynchrony using tissue velocities. 6 In a similar vein, our take on PROSPECT and ReTHINQ is that they do not convincingly repudiate the notion that a dyssynchronous heart is more likely to respond to CRT. In that regard it is heartening to see a study examine the value of using multiple parameters to predict response to CRT. Lafitte and colleagues examined parameters of dyssynchrony at multiple functional levels including atrioventricular, interventricular and intraventricular. 7 The strengths of this study include: size (n ¼ 181), multicentre design, all patients fulfilled standard clinical criteria for CRT (New York Heart Association class II–IV, ejection fraction, 35%, and QRS width. 120 ms) and a large proportion of ‘responders’ to CRT (57%). The authors used a relatively well-validated index of response, namely a 15% decrease in left ventricular endsystolic volume. Feasibility of measurement was high (80%) at acceptable variability of 9%. The primary incremental finding of this study is that false-positive predictive rates decreased from 14% when using one parameter to 1% when using four parameters. Using 3 parameters resulted in a specificity. 90% and a positive predictive value of. 65%. Only 4% of patients with no positive criteria responded to CRT. Lastly, the authors noted a relationship between reverse remodelling and number of parameters found to be positive, ie patients with more dyssynchrony demonstrated more pronounced reverse remodelling after CRT. These strengths are tempered by a number of limitations. This is an observational study. Whether this study cohort is representative of the general population or the population enrolled in the large CRT trials is unclear. Non-responder rates were somewhat higher than those previously reported (50% vs. 30%, respectively). 8, 9 The proportion of patients with 3 echocardiographic parameters was low. Sensitivity rates were low. Some of the parameters in their algorithm, such as septal to posterior wall motion delay by M-mode, may be challenging to obtain and may be ineffectual in an infarct population. Other parameters, such as systo-diastolic overlap, are ill defined and not well validated. The authors also use tissue velocity-based indices that have been much maligned (with or without good cause) after PROSPECT. Indeed, some work suggests even visual assessment of dyssynchrony is superior to tissue velocity-based analysis. 10 Other echocardiographic parameters such as severity of mitral regurgitation, global diastolic function, or regional diastolic dyssynchrony were not assessed. This paper also does not inform the readers as to whether the parameters tested provide independent and/or incremental value over each other. It may be more informative to test …
