Pcsk9 is associated with severity of coronary artery lesions in male patients with premature myocardial infarction

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 (Pcsk9) correlated with incidence and prognosis of coronary heart disease. However, it is unclear whether Pcsk9 contributed to coronary artery lesion severity in patients with premature myocardial infarction (PMI). The present study investigated associations between Pcsk9 and coronary artery lesion severity in PMI patients who underwent coronary angiography (CAG).

METHODS

This prospective cohort study included young men (age ≤ 45 years, n = 332) with acute MI who underwent CAG between January 2017 and July 2019. Serum Pcsk9 levels and clinical characteristics were evaluated. SYNTAX scores (SYNergy between percutaneous coronary intervention with [paclitaxel-eluting] TAXUS stent and cardiac surgery) were calculated to quantify coronary artery lesions.

RESULTS

Serum Pcsk9 levels were positively associated with SYNTAX scores (r = 0.173, P < 0.05). The diagnostic cutoff value of PSCK9 level was 122.9 ng/mL, yielding an area under the curve (AUC) of 0.63, sensitivity 81%, and specificity 40%. Serum Pcsk9, LDL-C, Apob, NT-proBnp, CK level, and diabetes history were independent predictors of high SYNTAX scores (P < 0.05). After stratifying by serum LDL-C level (cutoff = 2.6 mmol/L), medium-high Pcsk9 levels had increased risk of high SYNTAX scores in patients with high LDL-C (P < 0.05), and higher serum Pcsk9 levels had increased risk of major adverse cardiac events (MACE) after adjusting for confounding factors (P < 0.05).

CONCLUSION

Serum Pcsk9 levels correlates with severity of coronary artery lesion in PMI patients and may serve as a biomarker for severity of coronary artery stenosis in this patient population, which may contribute to risk stratification.

Hyperhomocysteinemia as the only risk factor in a young man presenting with ST-elevation myocardial infarction

Hyperhomocysteinemia has been established as a risk factor for cardiovascular events. This case of a 23-year-old male, presenting with acute coronary thrombosis and unremarkable past medical history, highlights the importance of measuring homocysteine levels in young individuals with acute coronary syndromes, especially those without conventional risk factors. <Learning objective: Hyperhomocysteinemia could be rarely the only risk factor causing an acute coronary syndrome, especially in very young individuals; Optical coherence tomography could provide valuable information regarding the cause of occlusion in an unexpected clinical presentation; Gene testing for thrombophilia should be considered for very young individuals with acute coronary syndrome without conventional risk factors; Randomized controlled trials have failed to prove a clinical benefit in patients treated with folic acid.>.

Genetic polymorphisms in early-onset myocardial infarction in a sample of Iraqi patients: a pilot study

OBJECTIVES

Early-onset myocardial infarction constitutes nearly one third of cases of myocardial infarction among Iraqis, which is rather higher than the proportions reported in many Western countries. Thus this study was initiated to investigate the role of some genetic polymorphisms, as well as acquired risk factors in this condition.

RESULTS

A total of 102 Iraqi patients with first myocardial infarction aged 50 years, and 77 matched controls were enrolled. The DNAs of participants were screened for nine polymorphisms, namely: β-Fibrinogen (- 455G > A), Factor XIII (V34L), Plasminogen Activator inhibitor-1 (PAI-1, 4G/5G), Human Platelet Antigen-1 (HPA1a/b), 5,10-Methylenetetrahydrofolate Reductase MTHFR (C677T) and MTHFR (A1298C), Angiotensin-Converting Enzyme (ACE) 287 bp insertion/deletion (I/D), Apolipoprotein-B (ApoB: R3500Q), and Apolipoprotein-E (Apo E: E2/E3/E4), using PCR and reverse hybridization technique. Among traditional risk factors, univariate analysis revealed that smoking (OR 2.86 [95%CI 1.53-5.34]), hyperlipidemia (OR 5.23 [95%CI 2.66-10.29]), and diabetes mellitus (OR 4.05 [95% CI 1.57-10.41]) were significantly higher among patients compared to controls (P<0.001, <0.001 and 0.002 respectively), while none of the nine genetic polymorphisms reached significance. Multivariate Logistic regression, however, revealed that only smoking and hyperlipidemia retained significance (P of < 0.001 each). The need to initiate further studies on larger cohorts is paramount to understand the higher than expected frequency of early-onset myocardial infarction in our population.

Differences in Baseline Characteristics and Outcomes in Young Caucasians and African Americans with Acute Myocardial Infarction

BACKGROUND

The incidence of acute myocardial infarction (AMI) in young patients is increasing. While race-related differences in clinical characteristics and outcomes for older AMI patients have been well-studied, such differences in young patients are unknown.

METHODS

We performed a retrospective review of charts of Caucasian and African American (AA) patients <50 years of age, presenting with AMI between 2010 and 2017 in an urban, community hospital in Detroit, Michigan.

RESULTS

A total of 271 patients were identified with 156 being AAs (57.5%). Mean age was 43 years which was similar in both groups. AAs with AMI were 2.2 times more likely to be women and to have a history of diabetes and 1.2 times more likely to have BMI >30 kg/m². History of coronary artery disease (1.8-fold) and hypertension (1.5-fold) were also more common in AAs. Overall presenting features were similar, other than that AAs presented more often with non-ST-elevation MI and tended to present less often with cardiac arrest. No differences were observed in the angiographic findings or in-hospital outcomes in the two groups, with the exception of lower need of mechanical support in AAs.

CONCLUSIONS

In conclusion, our data provide important, not previously described information on race-related differences in history, presentation, clinical and angiographic features and outcomes in AAs compared with Caucasians younger than 50 with AMI. These findings may have implications for tailoring specific preventive strategies to decrease the incidence of AMI and its associated adverse events in both racial groups.

Cannabis-induced recurrent myocardial infarction in a 21-year-old man: a case report

BACKGROUND

Acute coronary syndrome (ACS) is rarely caused by coronary artery disease in young patients unless cardiovascular risk factors are present. Although non-atherosclerotic causes of ACS are rare, they need to be considered in young patients.

CASE SUMMARY

We report on a 21-year-old patient referred to our institution with ACS. Electrocardiogram showed ST-segment elevation and coronary angiography revealed thrombotic occlusion of the left anterior descending artery. Reperfusion was achieved by thrombus aspiration, glycoprotein IIb/IIIa inhibitors (GPI), and drug-eluting stent (DES). The patient had no cardiovascular risk factors but reported cannabis consumption before symptom onset. Although he was put on dual antiplatelet therapy and strictly advised to avoid consumption, he continued to abuse cannabis and suffered three further ACS events within 18 months: the first 8 months later caused by thrombotic occlusion of a diagonal branch treated by GPI and DES, the second after 17 months due to thrombotic re-occlusion of the diagonal branch, and the third after 18 months by thrombotic occlusion of the circumflex artery, both events treated by GPI alone (all while still using cannabis). Since then, he stopped cannabis consumption and has been symptom-free for 8 months.

DISCUSSION

This case highlights that cannabis-induced ACS must be considered as a cause of myocardial infarction in young adults. In contrast to ACS in the elderly population, this unusual ACS cause requires specific treatment. The risk of ACS relapse may substantial if cannabis abuse is continued. This potential hazard needs to be taken into consideration when legalization of cannabis is discussed.

Effects of familial hypercholesterolemia-associated genes on the phenotype of premature myocardial infarction

Background

The incidence of premature myocardial infarction (PMI) has gradually increased in recent years. Genetics plays a central role in the development of PMI. Familial hypercholesterolemia (FH) is one of the most common genetic disorders of cholesterol metabolism leading to PMI.

Objective

This study investigated the relationship between FH-associated genes and the phenotype of PMI to clarify the genetic spectrum of PMI diseases.

Method

This study enrolled PMI patients (n = 225) and detected the mutations in their FH-associated genes (LDLR, APOB, PCSK9, LDLRAP1) by Sanger sequencing. At the same time, patients free of PMI (non-FH patients, n = 56) were enrolled as control, and a logistic regression analysis was used to identify risk factors associated with PMI. The diagnosis of FH was confirmed using “2018 Chinese expert consensus of FH screening and diagnosis” before the prevalence and clinical features of FH were analyzed.

Results

Pathogenic mutations in LDLR, APOB, PCSK9 and LDLRAP1 genes were found in 17 of 225 subjects (7.6%), and all mutations were loss of function (LOF) and heterozygous. The genotype-phenotype relationship of patients carrying FH-associated mutations showed high heterogeneity. The logistic regression analysis showed that the smoking history, obesity and the family history of premature CHD were independent risk factors of PMI. In this study, a total of 19 patients (8.4%) were diagnosed as FH, and the proportion of smoking subjects in FH patients was higher than that in non-FH patients.

Conclusions

FH-associated gene mutations were present in about 7.6% of Chinese patients with PMI. In addition to genetic factors, smoking history, lifestyle and other environmental factors may play a synergistic role in determining the phenotype of PMI.

Trial registration

Essential gene mutation of cholesterol metabolism in patients with premature myocardial infarction. ChiCTR-OCH-12002349.Registered 26 December 2014, http://www.chictr.org.cn/showproj.aspx?proj=7201.

Prevalence of heterozygous familial hypercholesterolemia and combined hyperlipidemia phenotype in very young survivors of myocardial infarction and their association with the severity of atheromatous burden

BACKGROUND

Heterozygous familial hypercholesterolemia (HeFH) and combined hyperlipidemia (CHL) phenotype are associated with premature myocardial infarction (MI).

OBJECTIVE

To assess the prevalence of HeFH and CHL phenotype among young survivors of MI and compare patients' characteristics with these 2 lipid disorders.

METHODS

We recruited 382 young survivors of MI (≤40 years). Fasting lipids, lipoprotein(a) [Lp(a)], apolipoprotein A-1, and apolipoprotein B (apoB) levels were determined. Using the Dutch Lipid Clinic Network (DLCN) algorithm, patients having definite or probable HeFH were identified. Patients with apoB levels >120 mg/dL and triglyceride levels >170 mg/dL (1.92 mmol/L) [>90th percentile of 326 age and sex-matched healthy controls] were classified as having CHL phenotype. Common carotid artery intima-media thickness (CCA-IMT) was measured by B-mode ultrasonography.

RESULTS

Eighty-one patients (21.2%) had definite/probable HeFH and 62 (16.2%) had CHL phenotype. Twenty-three patients fulfilled the criteria for both HeFH and CHL phenotype and were removed from further comparisons. Patients with HeFH (n = 58) had higher levels of total cholesterol, low-density lipoprotein (LDL)-cholesterol, Lp(a), and apoB, whereas patients with CHL phenotype (n = 39) had higher levels of triglycerides and lower high-density lipoprotein (HDL)-cholesterol levels. The prevalence of metabolic syndrome was higher in patients with CHL phenotype compared to those with HeFH (67.0% vs 16.4%, P < .001). Patients with HeFH had more extensive coronary artery disease (3-vessel disease: 36.2% vs 12.8%, P = .011) and greater right CCA-IMT (0.67 ± 0.11 mm vs 0.56 ± 0.09 mm, P < .001) and left CCA-IMT (0.68 ± 0.10 mm vs 0.56 ± 0.08 mm, P < .001) compared to CHL phenotype patients.

CONCLUSIONS

Both HeFH and CHL phenotype are common among patients with premature MI. CHL phenotype compared to HeFH is associated with less atheromatous burden in coronary and carotid arteries at the time of first MI.

High levels of lipoprotein (a) and premature acute coronary syndrome

BACKGROUND AND AIMS

High levels of lipoprotein(a) [Lp(a)] are associated with increased risk of acute coronary syndrome (ACS). We explored whether Lp(a) exhibits a stronger association with premature ACS.

METHODS

A case-control study was conducted; 1457 patients with a history of ACS (54.8 ± 13 years, 86% males) and 2090 age-sex matched adults free of cardiovascular disease were enrolled. Bio-clinical characteristics [risk factors, low-density lipoprotein-cholesterol, Lp(a)] were derived through standard procedures.

RESULTS

A 10 mg/dL increase in Lp(a) was associated with 4% (95% CI, 1.01 to 1.02) higher likelihood of having ACS in younger (<45 years) and 2% (95% CI, 1.01 to 1.02) higher likelihood in middle-aged (45-60 years) individuals. Adjusting for common risk factors, elevated Lp(a), i.e. >50 mg/dL, was still associated with increased likelihood of ACS in younger adults (<45 years) (OR = 2.88, 95% CI, 1.7 to 4.6) and in middle aged ones (45 and 60 years) (OR = 2.06, 95% CI, 1.4 to 3.2), but not in older participants (>60 years) (OR = 1.31, 95% CI, 0.8 to 2.4).

CONCLUSIONS

Lp(a) seems to be an independent risk factor for ACS in individuals <45 years, and high Lp(a) levels increase by ∼3folds the risk for ACS. The association is preserved but is less in middle-aged individuals (45-60 years) and is abolished >60 years.

Circadian pattern of symptoms onset in patients ≤35 years presenting with ST-segment elevation acute myocardial infarction

BACKGROUND

There are scarce data regarding the circadian pattern of symptoms onset in young patients presenting with acute myocardial infarction (AMI). We explored whether young patients with ST-segment elevation AMI exhibit a circadian variation in symptoms onset.

METHODS

We recruited prospectively 256 consecutive patients who had survived their first ST-segment elevation AMI ≤35 years of age. Patients were categorized into 4 groups by 6-h intervals over 24 h.

RESULTS

In 49 patients (19.1%) the clinical presentation of AMI was atypical. The symptoms onset was as follows: 00:01 to 06:00, 19.1%, 06:01 to 12:00, 32.4%; 12:01 to 18:00, 28.1%; and 18:01 to 24:00, 20.3%. There was a significant association between the time of day and the likelihood of symptoms onset (Rayleigh test, p<0.001). Between 00:01 and 06:00 the incidence of AMI onset was lower than expected and between 06:01 and 12:00 was higher (p=0.034 and p=0.011, respectively), whereas in the other 6-h period groups no difference was found between expected and observed AMI incidence (p=0.280 and p=0.131). No significant differences were found regarding clinical characteristics, i.e. traditional risk factors, reperfusion treatment of AMI, ejection fraction of left ventricle, time interval from pain onset to hospital arrival, dietary habits and physical activity, among the 6-h period groups.

CONCLUSIONS

ST-segment elevation AMI in individuals ≤35 years of age follows a circadian pattern with a morning peak. This information might be useful for the prompt diagnosis and treatment of AMI in very young patients which occurs rarely and frequently with atypical clinical presentation.

Premature myocardial infarction is strongly associated with increased levels of remnant cholesterol

BACKGROUND

Remnant cholesterol has been defined as the cholesterol present in triglyceride-rich remnant lipoproteins. Elevated levels of remnant cholesterol have been associated with increased cardiovascular risk. Acute myocardial infarction (AMI) in very young individuals (≤40 years) represents a rare disease with a typical risk factor profile and a lipid phenotype that is characterized by a predominance of elevated triglyceride-rich lipoproteins.

OBJECTIVE

The aim of this study was to investigate the role of remnant cholesterol in premature AMI.

METHODS

We prospectively enrolled 302 patients into our multicenter case-control study comprising 102 consecutive myocardial infarction survivors (≤40 years) and 200 hospital controls. Myocardial infarction patients were frequency matched for age, gender, and center. Remnant cholesterol was calculated from standard lipid parameters.

RESULTS

Remnant cholesterol was 1.7-fold higher in premature AMI patients compared with controls (61.1 ± 36.8 vs 35.8 ± 16.8 mg/dL; P < .001). Remnant cholesterol was the lipid fraction most strongly associated with premature myocardial infarction (odds ratio 3.87; 95% confidence interval 2.26-6.64; P < .001) for an increase of 1-standard deviation. This observation was independent from clinical risk factors and plasma lipid levels.

CONCLUSIONS

Remnant cholesterol is strongly associated with premature myocardial infarction, can be easily calculated, and might serve as a new potent risk marker in this young patient population.