Philip Chang, MD
Spence JD, Solo K. Resistant Atherosclerosis: The Need for Monitoring of Plaque Burden. Stroke. 2017
In this study, Spence and Solo demonstrated that measurement of LDL-C levels is likely inadequate to assess a patient’s response to statin therapy. In their database of 4512 patients with 2 measurements of LDL-C and 2 carotid duplex scans measuring total plaque area, they found that neither LDL-C levels nor change in LDL-C levels predicted carotid artery plaque burden or progression of plaque area. Interestingly, they found that in the 6% of patients with low LDL-C levels (<38mg/dL), almost half experienced progression of their plaque burden. In addition, they found that it was not uncommon for patients with LDL-C levels of over 70mg/dL to experience plaque regression. This suggests that merely relying on an LDL-C level to predict plaque burden is insufficient.
Cholesterol has been a moving target in the last several years, and this paper, along with others, shows that the target-to-treat approach of the ACC/AHA guidelines was less clinically useful than it had initially appeared to be. Therefore, in 2013, the ACC/AHA guidelines shifted focus from target LDL goals, but instead used disease conditions and risk-scores to help physicians determine when a statin is necessary. Ischemic stroke is included in the guideline definition for presence of clinical atherosclerotic cardiovascular disease, and high intensity statins are recommended for patients who are under 75 years old, while moderate intensity statins are recommended for patients who are over 75 or have an inability to tolerate high-intensity statins. In the case of ischemic stroke, SPARCL was the first trial to show that high-intensity statin treatment reduced the risk of recurrent ischemic stroke in patients with a history of TIA/stroke and an LDL-C above 100mg/dL (2.6mmol/L). People with a “normal” cholesterol in the 130s benefited from statin therapy as well in the SPARCL study. However, merely pouring high-intensity statins on all stroke patients may have some risk. For several years, there have been many studies suggesting lower LDL-C levels being associated with increased risk of spontaneous intracerebral hemorrhage, casting doubt on the one-size fits all approach to statin therapy for stroke patients.
Point to Ponder: You see a 70-year-old patient with hypertension and diabetes at the hospital who suffered an ischemic lacunar stroke, and was found to have an LDL of 70 (has never been on a statin) and moderate carotid artery atherosclerosis on carotid duplex. Would you start a high-intensity statin on such a patient? If so, would you order a follow-up duplex to assess effectiveness of therapy?