Israel Medical Association Journal

Background: Remnant cholesterol (RC), the cholesterol content of triglyceride-rich lipoproteins, is an emerging residual risk factor for atherosclerotic cardiovascular disease. Data on the prognostic significance after an ischemic stroke are limited.

Objectives: To investigate the association between RC and risk for cardiac events following hospitalization for an ischemic stroke.

Methods: Data were collected for 5697 patients (39.5% women) affiliated with Clalit Health Services and hospitalized with an acute ischemic stroke. Adjusted Cox-regression models were used to estimate the association between RC percentiles, calculated using a routine post-discharge lipid profile, and risk for future myocardial infarction (MI) or coronary revascularization.

Results: Mean age was 69 ± 10 years; 78% were treated by lipid-lowering therapies. During median follow-up of 22 months, a MI or coronary revascularization event occurred in 243 patients. After multivariable adjustment including lipid-lowering therapies and non-HDL-C, RC was associated with higher MI or revascularization risk: hazard ratio (95% confidence interval): 1.42 (1.10–1.85), 1.50 (1.11–2.02), 1.62 (1.09–2.40), and 1.93 (1.22–3.06), in those with RC percentiles ≥ 50th (23.3 mg/dl), ≥ 75th (31.8 mg/dl), ≥ 90th (42.1 mg/dl), and ≥ 95th (49.1 mg/dl), compared to < 50th percentile. When RC and non-HDL-C levels were discordant, the level of RC better reflected higher risk for adverse cardiac events.

Conclusions: Elevated RC following acute ischemic stroke is a risk factor for MI or coronary revascularization, independent of lipid-lowering therapies and non-HDL-C and may serve as a residual cardiovascular risk marker and potential treatment target in patients with ischemic stroke.

Despite the application of recommended guideline-driven therapies and optimal medical interventions, individuals with established cardiovascular disease remain susceptible to additional cardiovascular incidents, a phenomenon referred to as residual risk. Analyses of clinical trial data reveal significant residual cardiovascular risk in all treated patients, even in the setting of optimal LDL-C reduction, thus enforcing the need to revise the algorithms beyond focusing on LDL-C levels. We present a case that highlights the problem of residual risk upon well controlled LDL-C levels and provide insights for additional measures for residual risk reduction.

Background: Coronary heart disease (CHD) patients are considered high cardiovascular risks. Guidelines recommend low-density lipoprotein cholesterol (LDL-C) target levels below 55 mg/dl with > 50% reduction from baselines. These levels can be reached by a combination of statins, ezetimibe, and anti-protein convertase subtilisin/kexin type 9 (anti-PCSK9) agents. Our clinical impression was that CHD patients do not reach LDL-C target levels, despite the wide availability.

Objectives: To evaluate whether hospitalization would result in changes in lipid lowering regimens and short-term compliance.

Methods: We conducted a retrospective cohort study using data of CHD patients who were admitted to internal medicine wards at Clalit Health Services medical centers because of anginal syndrome during 2020–2022. The data were evaluated for demographic and clinical characteristics; LDL-C level at admission, 6 months previously, and 3 months and 6–9 months after discharge; rates of reaching LDL-C target levels; and lipid lowering treatment at admission, discharge, and 6–9 months after.

Results: The cohort included 10,540 patients. One-third and three-quarters did not have lipids level measurements up to 6 months before and during hospitalization, respectively. Only one-fifth of the patients reached LDL-C values before and during admission (median LDL-C 72 mg/dl; range 53–101). Approximately half were treated with high-dose potent statins. Only 10% were treated with ezetimibe. Hospitalization did not have a clinically significant effect on short-term lipid lowering treatment or LDL-C levels.

Conclusions: Gaps were noted between guidelines and clinical practice for reaching LDL-C target levels. Further education and strict policy are needed.

Background: The use of proprotein convertase subtilisin/kexin type 9 monoclonal antibodies (PCSK9 mAbs) is emerging for lowering low-density lipoprotein cholesterol (LDL-C). However, real-world data is lacking for their use among elderly patients.

Objective: To define the characteristics of elderly patients treated with PCSK9 mAbs and to evaluate the efficacy and tolerability compared with younger patients.

Methods: We conducted a retrospective cohort study of elderly patients (≥ 75 years at enrollment) treated with PCSK9 mAbs for primary and secondary cardiovascular prevention. Data were retrieved for demographic and clinical characteristics; indications for treatment; agents and dosages; concomitant lipid lowering treatment; LDL-C levels at baseline, 6, 12 months, and at the end of follow up. Data also included achieving LDL-C target levels and adverse effects.

Results: The cohort included 91 elderly patients and 92 younger patients, mean age 75.2 ± 3.76 and 58.9 ± 7.4 years (P < 0.0001). Most patients (82%, 80%) were in high/very high-risk categories. For almost all (98%, 99%), the indication was statin intolerance, with PCSK9 mAb monotherapy the most prevalent regimen. The average follow-up was 38.1 ± 20.5 and 30.9 ± 15.8 months (P = 0.0258). Within 6 months the LDL-C levels were reduced by 57% in the elderly group and by 59% in the control group (P = 0.2371). Only 53% and 57% reached their LDL-C target levels. No clinically significant side effects were documented.

Conclusion: PCSK9 mAbs have similar effects and are well tolerated among elderly patients as in younger patients.

Background: While earlier studies indicated that cholesterol levels decrease significantly after an acute myocardial infarction (MI), a more recent study refuted this observation. 

Objectives: To assess changes in plasma lipid levels after onset of acute MI, and determine important predictors of lipid dynamics.

Methods: We prospectively measured lipid levels of patients who presented with an acute MI. Blood samples were drawn on admission to the hospital (day 1), after fasting at least 12 hours overnight (day 2), and on the 4th day of hospitalization (day 4). 

Results: Of 67 acute MI patients, 30 were admitted for ST elevation MI (STEMI) and 37 for non-STEMI. Both total cholesterol and low density lipoprotein cholesterol (LDL-C) levels decreased significantly (by 9%) in the 24 hours after admission and by 13% and 17% respectively on day 4. High density lipoprotein cholesterol (HDL-C) levels as well as triglycerides did not change significantly. Independent predictors of LDL-C decrease were the presence of diabetes mellitus [odds ratio (OR) 6.73, P = 0.01), and elevated cardiac troponin T (cTnT) levels (OR 1.81, P < 0.04).

Conclusions: LDL-C levels decrease significantly after an acute MI. The reduction is correlated with cTnT levels. Diabetes is a strong independent predictor of LDL-C decrease. In acute MI patients only measurements taken within 24 hours of onset should be used to guide selection of lipid-lowering medication.

 

Background: Several murine models are susceptible to atherosclerosis, such as low density-lipoprotein receptor-deficient (LDLR^-/-) and apolipoprotein E-deficient (apoE^-/-) mice, and are used for studying pathophysiological mechanisms. Atherosclerotic lesions in the aortic valve and thoracic/abdominal aorta are commonly associated with hyperlipidemia. We recently demonstrated the development of large atherosclerotic plaques in Helicobacter pylori-infected heterozygous LDLR^+/- apoE^+/- mice.

Objectives: To measure novel biomarkers related to atherosclerosis, blood coagulation, and oxidative stress in order to investigate their possible pathogenic roles in atherosclerosis-prone mice.

Methods: Mice were fed with a normal chow diet or high-fat diet and sacrificed at different age intervals to measure aortic plaque size. Plasma cholesterol was enzymatically measured. Enzyme-linked immunosorbent assay was used to measure oxidized LDL (oxLDL)/beta-2-glycoprotein I (β2GPI) complexes, immunoglobulin M (IgM) antibodies against native LDL, oxLDL, or oxLDL/β2GPI, and urine 11-dehydro-thromboxane B₂ (11-dhTxB₂) or 8-hydroxy-deoxyguanosine.

Results: There was a parallel increase in plaque size, plasma cholesterol, and urinary 11-dhTxB₂ in atherosclerosis-prone mice. In contrast to atherosclerosis-prone strains, an elevation of urinary 11-dhTxB₂ with no significant plaque generation was observed in LDLR^+/- apoE^+/- mice. The atherogenic autoantigen oxLDL/β2GPI complex was detected only in LDLR^-/- mice. These levels seem to depend on plaque size. IgM antibodies against oxLDL in apoE^-/- mice were found, accompanied by atherosclerotic progression.

Conclusions: Progression of atherosclerotic lesions was associated not only with cholesterolemia but also with platelet activation and natural autoimmune-mediated regulatory mechanism(s) in murine models.
 

Background: The introduction of more potent statins such as atorvastatin and rosuvastatin in Israel was accompanied by massive advertising about their superiority.

Objectives: To assess the need for switching therapy from older statins to more potent ones among diabetic patients with uncontrolled hypercholesterolemia.

Methods: Data on all diabetic patients over 30 years old attending two urban clinics were extracted and analyzed. For each patient we checked the last low density lipoprotein-cholesterol measurements for the year 2006, the brand and the dose of cholesterol-lowering medications, prescriptions and actual purchasing over a 4 month period prior to the last LDL-C[1] measurement, and whether treatment changes were necessary to achieve the LDL-C target (100 mg/dl or 70 mg/dl).

Results: The study population comprised 630 patients, age 66.7 ± 12.6 years, of whom 338 (53.6%) were women. Of the 533 (84.6%) patients whose LDL-C was measured in 2006, 45 (8.1%) had levels < 70 mg/dl and 184 (33.3%) had levels of 70 mg/dl < LDL-C < 100 m/dl.  The reasons for LDL-C > 100 mg/dl were patients not prescribed cholesterol-lowering drugs (38.3%), partial compliance (27.2%), and under-dosage of statins (15.4%); only 7.7% needed to switch to a more potent statin. Reasons for LDL-C > 70 mg/dl were patients not prescribed cholesterol-lowering drugs (34.3%), partial compliance (22.0%), and under-dosage of statins (26.6%); only 8.7% needed to switch to a more potent statin.

Conclusions: Only a small minority of diabetic patients with uncontrolled hypercholesterolemia need one of the potent statins as the next treatment step. More emphasis on compliance and dose adjustment is needed to achieve the target LDL-C level.

Objectives: To examine whether the treatment recommendations given to ischemic heart disease patients at hospital discharge are compatible with the guidelines of the Israeli Medical Societies and the U.S. National Cholesterol Education Program for coronary artery disease prevention; and to study the effects of brief educational sessions on the adherence of physicians with the guidelines.

Methods: We included consecutive IHD[1] patients admitted to four central hospitals in Israel between 1998 and 2000. The study was conducted in two phases. In phase 1, we reviewed discharge letters to document treatment recommendations given to each patient. In phase 2 we educated the practitioners by reviewing the Israeli Medical Societies and the NCEP[2] guidelines and the quality of their recommendations in phase 1, after which we reevaluated the discharge letters.

Results: The study included 2,994 patients: 627 in phase 1 and 2,367 in phase 2. Of the patients who needed cholesterol-lowering according to their low density lipoprotein levels, 37.4% were not prescribed such drugs at discharge (under-treatment group). This proportion was reduced by education to 26.6% (P < 0.001) in phase 2. Of the treated patients, 65.6% did not reach the target LDL[3] goal in phase 1 (under-dosage group) as compared to 60.2% in phase 2 (P = 0.23). In phase 2 there was an increase in the percent of patients reaching LDL levels <130 mg/day (69.3% vs. 63.8% of patients prescribed medication, P = 0.01), but the percent of patients reaching LDL levels <100 was not different in phase 2 after adjusting for age and gender (the odds ratio for reaching target LDL was 1.16, with 95% confidence interval of 0.95–1.43).

Conclusions: Physician recommendations to IHD patients discharged from hospital were suboptimal. We documented a high proportion of under-treated and under-dosage patients. Brief educational sessions have a beneficial effect on the usage of statins; however, additional effort in guideline implementations is needed.

Background: Low density lipoprotein apheresis is used as a complementary method for treating hypercholesterolemic patients who cannot reach target LDL[1]-cholesterol levels on conventional dietary and drug treatment. The DALI system (direct absorption of lipoproteins) is the only extracorporeal LDL-removing system compatible with whole blood.

Objective: To describe our one year experience using the DALI[2] system.

Methods: LDL apheresis was used in 13 patients due to inability to reach target LDL-C levels on conventional treatment. They included seven patients with familial hypercholesterolemia, three who had adverse reactions to statins, and three patients with ischemic heart disease who did not reach LDL-C target level on medical treatment.

Results: The average triglyceride, total cholesterol, high density lipoprotein-C and LDL-C levels before and after treatment in all patients were: 170 ± 113 vs. 124 ± 91, 269 ± 74 vs. 132 ± 48, 42 ± 8 vs. 37 ± 7.9, and 196 ± 77 vs. 80 ± 52 mg/dl, respectively. Comparing the results of a subgroup of seven patients who had previously been treated with plasma exchange, it is noteworthy that while the reduction in triglyceride, total cholesterol and LDL-C are comparable, the effect on HDL[3]-C concentration was less apparent: from an average of 39.7 ± 8.7 and 23 ± 5.7 mg/dl before and after plasma exchange to an average of 43.9 ± 8.1 and 38.4 ± 7 mg/dl before and after LDL apheresis, respectively. Five patients developed treatment-related adverse events: three experienced allergic reactions manifested as shortness of breath, urticaria and facial flushing; one patient developed rhabdomyolysis, an adverse reaction that was not reported previously as a result of LDL apheresis; and one patient had myopathy with back pain. All untoward effects occurred during the first few treatment sessions.

Conclusions: LDL apheresis using the DALI system is highly efficacious for the treatment of hypercholesterolemia. It is associated with a significant number of side effects occurring during the first treatment sessions. In patients not experiencing adverse effects in the early treatment period, it is well tolerated, and can provide remarkable clinical benefit even after short-term therapy.

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Background: Hyperlipidemia is a major risk factor for coronary heart disease. Reducing low density lipoprotein-cholesterol can significantly reduce the risk of CHD[1], but many patients fail to reach the target LDL-C[2] goals due to low doses of statins or low compliance.

Objectives: To treat high risk patients with atorvastatin in order to reach LDL-C goals (either primary or secondary prevention) of the Israel Atherosclerosis Society.

Methods: In this open-label study of 3,276 patients (1,698 of whom were males, 52%), atorvastatin 10 mg was given as a first dose, with follow-up and adjustment of the dose every 6 weeks. While 1,670 patients did not receive prior hypolipidemic treatment, 1,606 were treated with other statins, fibrates or the combination of both.

Results: After 6 weeks of treatment, 70% of the patients who did not receive prior hypolipidemic medications and who needed primary prevention reached target LDL-C levels. Interestingly, a similar number of patients on prior hypolipidemic treatment reached the LDL-C goals for primary prevention. The patients treated with other statins, fibrates or both did not reach the LDL-C treatment goals. Only 34% of all patients who needed secondary prevention reached the ISA[3] LDL-C target of 100 mg/dl. Atorvastatin proved to be completely safe; only two patients had creatine kinase elevation above 500 U/L, and another six had mild CK[4] elevation (<500 U/L). None of the patients had clinical myopathy, and only one had to be withdrawn from the study.

Conclusion: Atorvastatin is a safe and effective drug that enables most patients requiring primary prevention to reach LDL-C goal levels, even with a low dose of 10 mg. Patients in need of secondary prevention usually require higher doses of statins.

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Background: Information is lacking on the effects of hormone replacement therapy in women with diabetes, especially during moderate chronic hyperglycemia.

Objectives: To study the effects of HRT on the lipid profile and the low density lipoprotein subclass distribution in women with type 2 diabetes under satisfactory and non-satisfactory glycemic control.

Methods: Fifty-four postmenopausal women after a 6 week run-in diet were randomized to receive either placebo(HbAlc <8%, n=13 HbAlc >8%, n=17) or HRT (HbAlc<8%, n=11 HbAlc >8%, n=13) for 12 weeks. HRT consisted of cyclical conjugated estrogens 0.625 mg/day plus medrogestone 5 mg/day. At the beginning and at the end of each treatment period the LDL subclass distribution was estimated by density gradient ultracentrifugation.

Results: At the baseline and during the study, the HbAlc level was significantly higher in hyperglycemic patients than in the near-normoglycemic controls (baseline 10.2±2.9 vs. 6.5±0.7%, P<0.01). They showed a trend for higher total and LDL cholesterol, triglycerides and lower high density lipoprotein-cholesterol compared to near-normoglycemic con­trols, as well as significantly higher triglyceride concentrations in very low density lipoprotein, intermediate density lipoprotein and LDL-1 particles and cholesterol content in LDL-1 and -2 particles. HRT decreased LDL-cholesterol in both groups. In the normoglycemic patients a small increase in HbAlc was observed (6.5±0.7 vs. 7.4+1%, P=004). In all cases, HRT did not modify the proportion of LDL represented by denser LDLs.

Conclusions: HRT did not modify the LDL subclass distribution, even in the presence of moderate chronic hyperglycemia in women with type 2 diabetes.