Aya Egbaria1, Walid Saliba1,2, Barak Zafrir3,4. 1. Faculty of Medicine, Technion, Israel Institute of Medicine,, Haifa, Israel. 2. Department of Community Medicine and Epidemiology, Lady Davis Carmel Medical Center, Haifa, Israel. 3. Faculty of Medicine, Technion, Israel Institute of Medicine,, Haifa, Israel. barakzmd@gmail.com. 4. Department of Cardiology, Lady Davis Carmel Medical Center, Haifa, Israel. barakzmd@gmail.com.
Abstract
PURPOSE: Recent guidelines recommend further reduction of low-density lipoprotein cholesterol (LDL-C) in high-risk populations. The use of proprotein convertase subtilisin/kexin type-9 inhibitors (PCSK9i) enables many patients to achieve profound reduction in LDL-C. However, in patients with low cholesterol, the commonly used Friedewald equation tends to underestimate LDL-C, which may result in undertreatment. We aimed to compare Friedewald LDL-C estimation with the more novel Martin/Hopkins method in PCSK9i-treated patients achieving low LDL-C. METHODS: We investigated high-risk patients treated by PCSK9i in whom Friedewald LDL-C levels were < 70 mg/dL and triglycerides ≤ 300 mg/dL. LDL-C was additionally assessed by the Martin/Hopkins method. The compatibility between estimations was evaluated using methods of concordance and reclassification between LDL-C categories (< 25, 25-40, 40-55, 55-70 mg/dL) and according to triglyceride strata. RESULTS: Mean age was 65 ± 10 years. The correlation coefficient between LDL-C estimations was r = 0.898. Martin/Hopkins reclassified 269 of the 608 patients (44%) to a higher LDL-C category, with 14% of the patients reaching LDL-C > 70 mg/dL. Of the 390 patients achieving Friedewald LDL-C < 55 mg/dL, 113 (29%) were estimated to have LDL-C ≥ 55 mg/dL by the Martin/Hopkins equation. The magnitude of discordance between LDL-C estimates was more pronounced in hypertriglyceridemic patients in whom LDL-C reclassification from < 55 to ≥ 55 mg/dL was observed in 48%. CONCLUSIONS: In real-world practice of high-risk patients achieving low LDL-C under PCSK9i, Martin/Hopkins algorithm displayed significant proportion of LDL-C upward discordance compared to the Friedewald equation, particularly observed in patients with elevated triglycerides, identifying patients that may need treatment intensification.
PURPOSE: Recent guidelines recommend further reduction of low-density lipoprotein cholesterol (LDL-C) in high-risk populations. The use of proprotein convertase subtilisin/kexin type-9 inhibitors (PCSK9i) enables many patients to achieve profound reduction in LDL-C. However, in patients with low cholesterol, the commonly used Friedewald equation tends to underestimate LDL-C, which may result in undertreatment. We aimed to compare Friedewald LDL-C estimation with the more novel Martin/Hopkins method in PCSK9i-treated patients achieving low LDL-C. METHODS: We investigated high-risk patients treated by PCSK9i in whom Friedewald LDL-C levels were < 70 mg/dL and triglycerides ≤ 300 mg/dL. LDL-C was additionally assessed by the Martin/Hopkins method. The compatibility between estimations was evaluated using methods of concordance and reclassification between LDL-C categories (< 25, 25-40, 40-55, 55-70 mg/dL) and according to triglyceride strata. RESULTS: Mean age was 65 ± 10 years. The correlation coefficient between LDL-C estimations was r = 0.898. Martin/Hopkins reclassified 269 of the 608 patients (44%) to a higher LDL-C category, with 14% of the patients reaching LDL-C > 70 mg/dL. Of the 390 patients achieving Friedewald LDL-C < 55 mg/dL, 113 (29%) were estimated to have LDL-C ≥ 55 mg/dL by the Martin/Hopkins equation. The magnitude of discordance between LDL-C estimates was more pronounced in hypertriglyceridemic patients in whom LDL-C reclassification from < 55 to ≥ 55 mg/dL was observed in 48%. CONCLUSIONS: In real-world practice of high-risk patients achieving low LDL-C under PCSK9i, Martin/Hopkins algorithm displayed significant proportion of LDL-C upward discordance compared to the Friedewald equation, particularly observed in patients with elevated triglycerides, identifying patients that may need treatment intensification.