The role of surgical technique in determining the outcome of left ventricular reconstruction: a difficult assessment

Abstract

We read with interest the review article of Klein and coworkers [1] who provide interesting insights about the outcome of left ventricular reconstruction surgery using different surgical techniques. In their article, the authors used a pooled-data analysis from a subset of studies within the total amount of 62 articles retrieved. This analysis, which included a fuddled number of patients, was designed to compare different surgical techniques in respect of early and late outcome. The authors concluded that the endoventricular reconstruction (EVR) technique demonstrated a reduced risk for early and late mortality compared to the linear repair (LR) technique. Pooled-data analysis is a powerful statistical tool aimed to achieve enough power from many underpowered studies. However, a prerequisite for this approach is that the choice of the technique should not be biased by different clinical conditions of the patients. The best practice should be pooling only data from randomized controlled trials, but we agree that they are practically absent in the literature. However, many studies included in this analysiswerebiasedbya surgical choice of the technique based on different size and extension of the left ventricular aneurysm: the general attitude was to use a LR for lesions not affecting the interventricular septum, leaving the EVR to anteroseptal aneurysms with an important septal involvement [2—4]. We could retrieve 8 articles reporting a total of about 1000 patients where this bias was present. Other studies compared the two techniques in consecutive periods of time, generally with the LR performed in the first years, and the EVR in the last [5]. Of course, many technical improvements apart from the surgical technique have been achieved in recent years, and this could introduce another source of bias. Finally, and most important, the comparison was made between institutions routinely performing LR or EVR. As a consequence, the results may reflect