Maria Trinidad Soria-Florido et al. published the results of their study on high-density lipoprotein (HDL) function and coronary syndrome in Circulation. They showed that low amount of HDL sphingosine-1-phosphate (S1P) and apolipoprotein A-I and low cholesterol efflux capacity are associated with cardiovascular manifestations of angina. HDL function was studied by measuring cholesterol efflux capacity, S1P, and ApoA-I in apolipoprotein B-depleted plasma and they showed that impaired cholesterol function is associated with a higher risk of acute coronary syndrome (ACS), irrespective of HDL cholesterol (HDL-C) concentrations.

The investigators selected a subgroup of patients who were participating in PREDIMED study, which was a randomized clinical trial including patients with high cardiovascular risk factors to evaluate the effects of following a traditional Mediterranean Diet (TMD) on the primary prevention of cardiovascular outcomes. The primary endpoints were decided to be fatal or non-fatal myocardial infarction and/or fatal or non-fatal unstable angina. The committee responsible to adjudicate the events was blinded to the treatment. Dr. Trinidad et. al. implemented a nested 1:2 case-control design, matching two controls by age (±5 years), sex, body mass index, intervention group, and time-to-event. They obtained apolipoprotein B-depleted plasma samples and measured the HDL related activity in the sample.

The findings showed that except for plasma HDL-C concentrations and the levels of ApoA-I in HDL, all other HDL related biomarkers correlated weakly with each other. There was an almost linear correlation between all HDL related biomarkers (except for ApoA-IV) and the incidence of cardiovascular events. They also showed that there is a strong relationship between low cholesterol efflux capacity (CEC) and a higher incidence of myocardial infarction.

Previous studies have shown that there is an association between low CEC and ACS in hypertriglyceridemia patients, but Maria Trinidad Soria-Florido et al. showed that this association also exists in patients with normal triglyceride levels. Hypertriglyceridemia probably exaggerates the effect. They also showed that not only HDL-bound S1P can predict atherosclerotic lesions development and its extent, but also S1P levels in apolipoprotein B-depleted plasma is associated inversely with ACS risk.

The study was limited by the small sample size and lack of thorough evaluation of the HDL oxidative-inflammatory index.

Raphael et al. showed in a prospective cohort study, published in Circulation, that type 2 myocardial infarction (T2MI), defined as an acute imbalance between oxygen delivery to the myocardium and the demand of the myocardium in the absence of athero-thrombosis, is associated with higher all-cause mortality compared to type 1 myocardial infarction (T1MI) caused by athero-thrombotic events, with no difference between these 2 groups regarding cardiovascular death.

Raphael et al. retrospectively included 5,460 patients with high troponin levels (more than 0.01) and divided them into 2 groups of T1MI and T2MI. They followed up the patients for 5.5 years. Cases with prior MI were excluded from the analysis.

After including the cases, they retrospectively classified MI types by 2 cardiologists based on clinical signs and laboratory results. MI was defined by a rise and/or fall in cardiac troponin T (cTnT) associated with either ischemic symptoms, new/presumed new ECG changes, new imaging evidence of ischemia, or direct identification of intracoronary thrombus on angiogram or autopsy. The cardiologists defined T2MI based on elevated cardiac troponin without other necessary factors. Other different types of MI including procedure-related MI were categorized as T1MI. They encountered the first MI event as the main event in cases with multiple MI events. They further subclassified T2MI based on its cause to the following subclasses: Arrhythmia, hypotension, anemia, post-surgical status  (in the absence of other causes e.g., T1MI and arrhythmia), hypoxia, and other (including spontaneous coronary artery dissection, coronary embolism, coronary spasm, structural heart disease e.g., severe aortic stenosis and malignant hypertension). They prospectively gathered the information regarding the mortality cause in the patients from the available documents, and divided the cause of mortality into either cardiovascular or non-cardiovascular.

The results showed that 56% were adjudicated as T1MI and 43% as T2MI. Patients with T2MI were older, female gender predominant, with a higher prevalence of chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD) while patients with T1MI were more likely to present with other well known MI risk factors. They also showed a lower level of sufficient MI related medical treatment in the T2MI group compared to T1MI. The rate of MI in both types has shown a decrease in incidence in the population. The rate of all-cause mortality was calculated after sex and age adjustment, and results implicated that the all-cause mortality rate was significantly higher in T2MI compared to T1MI even after adjustments. They showed that the risk of cardiovascular death is the same in both T1MI and T2MI, which may indicate the necessity of better diagnosis and treatment of T2MI after an encounter.

There is a lack of information regarding the T2MI incidence and effect on mortality in the general population. Raphael et al. tried to add to our current knowledge regarding this common type of MI by addressing the effect of this condition on all-cause and cardiovascular mortality.

One of the major factors encountered as a limitation for this study may be the difficulty faced in the diagnosis of T2MI in the clinical setting. A question has still remained that if treatment of T2MI with the same treatment protocol as T1MI will help to decrease cardiovascular and all-cause mortality in the patient’s population.

11/6/2019- Joe X. Xie et. al recently published the results of a Veterans cohort study in Circulation. They were able to show a meaningful decline in the rate of important 4 post-PCI medication utilization (beta-blockers, statins, ACEI/ARB, and P2Y12 inhibitor) among Veterans in a follow-up period of 5 years, with the highest decrease in medication utility after the first year of PCI. They also showed continuous consumption of all these medications is associated with a decreased rate of major adverse cardiac events (MACE).

Medical therapy utilization and association between medical therapy and MACE were the study’s primary outcomes. They included 57,900 patients who underwent staged PCI, defined as PCI on a non-STEMI lesion and if the PCI is being performed on a segment that had not been treated before. They excluded patients who were in the setting of cardiogenic shock, those who did not survive the index hospitalization following PCI, patients who obtain all their medications outside the VA, or those with a documented allergy to any of the four medication classes of interest. The majority were white elderly males, they usually used tobacco (62%), and most of them had comorbidities including hypertension (89.4%), diabetes mellitus (47.1%), and hyperlipidemia (88.4%) as main comorbidity factors. The mean duration of follow-up was 5 years. During an average follow-up of 5 years, a total of 24,364 patients experienced MACE which was defined as the first occurrence of all-cause death, rehospitalization for MI, rehospitalization for stroke, or repeat revascularization throughout the follow-up. They found a statistically significant correlation between death reduction and stroke rehospitalization and medication utility up to 5 years after PCI but not rehospitalization for MI. In their analysis, Xie and his colleagues calculated that less than 60% of the patients undergoing PCI receive all 4 medication classes at discharge (β-blocker, statin, ACE inhibitor/ARB, and P2Y12 inhibitor), with a gradual decrease of medication utility for approximately 20% of statins, β-blockers, and ACE inhibitor/ARBs over the subsequent 5 years post-PCI. This rate was reported to decrease to approximately 70% for the use of P2Y12 inhibitors.

Previously, there was little evidence available concerning the rate of long-term use of medical therapy following PCI. It has been shown that there is a suboptimal medication adherence by patients 6-12 months after PCI. Xie et al. also showed that all the described medication therapy classes were associated with decrease in the MACE risk even at 5 years post-PCI. They also noticed that all 4 classes of medications were associated with decreased MACE rates.

The data shown by Xie et al. can help with understanding patient compliance to medications, and to implement methods to increase the compliance. Further studies for non-VA patients are recommended.

A randomized clinical trial that was conducted by Paul M Ridker et al. and published in NEJM showed that there was no meaningful association between low dose methotrexate (MTX) administration and a decrease in cardiovascular events. Additionally, MTX usage was associated with adverse effects. Continue reading →

A prospective cohort study that was conducted by Mohamed Farag et al. in European Heart Journal demonstrated that evaluating endogenous fibrinolysis in patients with acute coronary syndrome may help physicians identify high-risk patients developing recurrent cardiovascular events, especially among those treated with dual antiplatelet therapy (DAT) after primary percutaneous coronary intervention (PPCI). Continue reading →

A systematic review conducted by Kamal R. Mahtani et al in JAMA looked into the evidence of salt restriction recommendation on heart failure prognosis. The investigators evaluated previous trials but could not find a conclusive relationship between salt consumption and heart failure prognosis. Continue reading →

A retrospective cohort study performed by David P. Fisher and his colleagues was published in JAMA, showing that bariatric surgery in obese patients with diabetes was associated with a lower incidence of macrovascular events. Continue reading →

A multinational prospective cohort study performed by Barak Zafrir et al. and published in the European Heart Journal concluded that worse cardiovascular outcomes of atrial fibrillation (AF) were associated with heart failure with preserved ejection fraction (HFpEF) and heart failure with middle range ejection fraction (HFmrEF) but not associated with heart failure with reduced ejection fraction (HFrEF). Continue reading →

A study by Mee Kyoung Kim and her colleagues published in Circulation has shown that there is a graded association between the number of high variability parameters like fasting blood glucose and total cholesterol levels, systolic blood pressure, and body mass index and cardiovascular outcomes. They showed that the mentioned variables may be considered as independent predictors of mortality and cardiovascular events. Continue reading →