In this article, numerical simulations are used to analyze thermal intensification in a high efficiency heat exchanger/reactor operating in laminar flow regime. Studied configurations which combined wall macro deformations are characterized by external sinusoidal wall deformations and an internal swirled core. Special attention is paid to the swirl pitch influence on the thermo-hydraulic performances for a Reynolds number ranging from 200 to 1000. A detailed analysis of the different complex intensification mechanisms is carried out for several values of the swirling core by considering the flow topology and temperature distribution in cross-sections for a given Reynolds number (equal to 600). Results show the influence of the cross-averaged vorticity flux evolution along the flow path on the heat transfer and pressure drop throughout the whole heat exchanger/reactor. Finally, overall performances are assessed considering the Performance Evaluation Criteria (PEC) for the studied Reynolds number range. It is found that a PEC as high as 3.10 can be reached for the geometry characterized by the smallest pitch at Re = 1000, which is of great interest for process intensification involving heat exchanger/reactors.