Introduction:
Despite well-documented benefits of intensive lipid-lowering treatment, the use of statins in patients with chronic coronary syndrome remains suboptimal. Statin dose is often reduced after reaching low-density lipoprotein cholesterol (LDL-C) target.

Aim of the research:
The purpose of the study was to assess changes in LDL-C levels following lipid-lowering therapy reduction during cardiac rehabilitation (CR).

Material and methods:
A total of 162 patients with a very high cardiovascular risk (target LDL-C levels of < 55 mg/dl), in whom LDL-C levels were measured at the beginning and end of phase 2 of CR, were selected out of a single-centre retrospective registry of 518 patients.

Results:
Patients had no contraindications to continue high-dose lipid-lowering therapy. Prior to undergoing CR, 63 (38.9%) patients had reached their target LDL-C levels and the statin or ezetimibe dose was reduced in 18 patients, increased in 2 patients, and unchanged in 43 patients. During CR the mean LDL-C levels in the study group decreased significantly from 70.5 ±37.1 mg/dl to 56.2 ±21.5 mg/dl (p = 0.0002). Conversely, patients who had their lipid-lowering therapy reduced, showed a significant increase in their LDL-C levels from 32.6 ±13.2 mg/dl to 46.5 ±15.5 mg/dl (p = 0.0004), with 6 (33.3%) patients exceeding their target LDL-C levels. At CR completion, a total of 77 (47.5%) patients failed to maintain their target LDL-C levels (< 55 mg/dl).

Conclusions:
Reducing of well-tolerated lipid-lowering therapy may lead to the loss of target LDL-C levels. These results emphasise the importance of continuing lipid-lowering therapy at effective doses even after reaching target LDL-C levels.