Stress echocardiography: the long and winding road from meta-analysis to bedside

Abstract

In response to the article by Noguchi et al. (Int. J. Cardiovascular Imaging 21,[189][190][191][192][193][194][195][196][197][198][199][200][201][202][203][204][205][206][207] In this issue, Noguchi et al. perform yet another meta-analysis in order to address the issue of which test is better for stress echocardiography [1]. The subject is an important one, and the authors meritoriously go through an extensive, 20-years long journey across the stress echo literature to reach some evidence-based conclusions: exercise is not so bad, dobutamine is similar to exercise, and dipyridamole is similar to dobutamine.Yet, the numbers should have a clinical rationale behind them and the quality score that the Authors assigned to the papers (on the basis of methodological criteria) misses some important points. Firstly, any meta-analysis has the inherent 'bouillabaisse' bias. You put together many different fishes, and a rotten fish is enough to compromise the quality of the overall work. In addition, here the same fish is sometimes multiplied in the literature -and some patients from some centres are certainly represented more than once in different papers coming from the same Institution and included in the meta-analysis.Secondly, it has been shown, confirmed and reconfirmed over time that -for pharmacological stress echo -the sensitivity mirrors the dose [3,4]. With dipyridamole [5], dobutamine [6] and adenosine [7], the sensitivity increases with higher doses and with atropine co-administration. The high dose dipyridamole protocol together with atropine, is considered to be state-of-the art and it is recommended by 8-years old guidelines [8]. Yet, Noguchi et al. pool data of standard dose [9] with high dose[10] and high dose plus atropine [11]. Not surprisingly, vasodilator stress echo sensitivity will suffer. It is also interesting that the best results were obtained by the least used stress, such as pacingstress echo or even pacing trans-oesophageal stress echo. The less feasible the test, the more distant from the real world, the best the published results mirroring initial experience from selected patients series in highly academic-oriented environment.When statistical data are tempered with clinical insight and common sense the conclusions of the data can be more realistically described. Twenty-five years of experience show that stress echo results have a satisfactory diagnostic accuracy with a variety of physical (exercise), pharmacological (dobutamine and dipyridamole) and electrical stressors (pacingwhich can be today administered non-invasively in patients with permanent pacemaker). Stress echo sensitivity is critically dependent on dose with pharmacological stress. Particularly for what concerns vasodilators, only studies with high dose plus atropine [11] or accelerated high dose [12] should be compared for diagnostic purposes. Taking into account these data, it comes out that:1. The specificity is highest for dipyridamole when compared to exercise and dobutamineas shown by meta-analysis considering only head-to...

A comparison of the diagnostic value of 2D strain stress echocardiography, myocardial perfusion scintigraphy, and Duke treadmill score in patients suspected of coronary artery disease

“…On the other hand, an exhaustive meta‐analysis from 2005 concluded that adenosine SE is less sensitive than dobutamine and exercise SE . This statement has been questioned by proponents of vasodilator stress . 2D strain analysis has proved to be more sensitive than wall motion analysis, but a limitation to the technique is the relative low temporal resolution (50–90 frames per second) which—at least in theory—is a disadvantage when the heart rate is high, as it is during dobutamine infusion or exercise stress, but not during vasodilatation …”

“…17 This statement has been questioned by proponents of vasodilator stress. 18 2D strain analysis has proved to be more sensitive than wall motion analysis, but a limitation to the technique is the relative low temporal resolution (50-90 frames per second)…”

Imaging techniques and coronary artery disease –a review

“…40 Dipyridamole had superior specificity for CAD than ESE, DSE or dipyridamole SPECT, although the sensitivity is lower, especially for one-vessel disease. 33,40,41 The specificity of DSE can be enhanced by using high-dose protocols or by fiGUre 4 Calculation of wall motion segment index with DSE. All segments are observed at baseline, during low-dose dobutamine infusion, at peak heart rate and at recovery.…”