Effect of Lipoprotein (a) Levels on Long-term Cardiovascular Outcomes in Patients with Myocardial Infarction with Nonobstructive Coronary Arteries

https://doi.org/10.1016/j.amjcard.2021.05.003Get rights and content

The association between elevated lipoprotein(a) [Lp(a)] and poor outcomes in coronary artery disease (CAD) has been addressed for decades. However, little is known about the prognostic value of Lp(a) in patients with myocardial infarction with nonobstructive coronary arteries (MINOCA). A total of 1179 patients with MINOCA were enrolled and divided into low, medium, and high Lp(a) groups based on the cut-off value of 10 and 30mg/dL. The primary endpoint was major adverse cardiovascular events (MACE), a composite of all-cause death, nonfatal MI, nonfatal stroke, revascularization, and hospitalization for unstable angina or heart failure. Kaplan-Meier and Cox regression analyses were performed. Accuracy was defined as area under the curve (AUC) using a receiver-operating characteristic analysis. Patients with higher Lp(a) levels had a significantly higher incidence of MACE (9.5%, 14.6%, 18.5%; p = 0.002) during the median follow-up of 41.7 months. The risk of MACE also increased with the rising Lp(a) levels even after multivariate adjustment [low Lp(a) group as reference, medium group: hazard ratio (HR) 1.55, 95% confidence interval (CI): 1.02-2.40, p = 0.047; high group: HR 2.07, 95% CI: 1.32-3.25, p = 0.001]. Further, clinically elevated Lp(a) defined as Lp(a) ≥30 mg/dL was closely associated with an increased risk of MACE in overall and in subgroups (all p <0.05). When adding Lp(a) (AUC 0.61) into the Thrombolysis in Myocardial Infarction (TIMI) score (AUC 0.68), the combined model (AUC 0.73) yielded a significant improvement in discrimination for MACE (ΔAUC 0.05, p = 0.032). In conclusion, elevated Lp(a) was strongly associated with a poor prognosis in patients with MINOCA. Adding Lp(a) to traditional risk score further improved risk prediction. Our data, for the first time, confirmed the Lp(a) as a residual risk factor for MINOCA.

Section snippets

Methods

This was a single-center, prospective and observational cohort study of patients with MINOCA. From January 2015 to December 2019, a total of 23460 unique AMI patients with coronary angiography were consecutively admitted to Fuwai hospital, including non ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI). Patients were identified as having MINOCA if their diagnosis met the 4th universal definition of AMI 22 and the coronary angiogram did

Results

Similar with previous studies, we adopted the Lp(a) cut-off value of 10 and 30mg/dL and divided the patients with MINOCA as low, medium, and high Lp(a) groups [Low: Lp (a) <10 mg/dL, n = 366; Medium: 10 ≤ Lp(a) < 30 mg/dL, n = 463; High: Lp (a) ≥30 mg/dL, n = 350] (Figure 1). The plasma Lp (a) concentrations were skewedly distributed in the population (Figure 2). As shown in Table 1, patients with higher Lp(a) level were more often female and had higher values of TC, LDL-C, and ApoB. There were

Discussion

The present study, firstly, verified the prognostic power of the Lp(a) level in patients with MINOCA, and found that elevated Lp (a) was strongly associated with an increased risk of MACE after MINOCA. Incorporating Lp (a) to TIMI risk score further improved the outcome prediction. These data support the utility of Lp(a) for risk stratification in the contemporary real-world management of MINOCA.

MINOCA represents a distinct entity and the underlying mechanisms are varied and may include plaque

CRediT Author Statement

Side Gao M.D.: Conceptualization, Methodology, Investigation, Data collection, Data curation, Formal analysis, Writing-Original Draft; Wenjian Ma M.D.: Conceptualization, Methodology, Investigation, Data collection, Validation, Formal analysis, Writing-Reviewing and Editing; Sizhuang Huang M.D.: Investigation, Data collection, Writing-Reviewing and Editing; Xuze Lin M.D.: Investigation, Data collection, Writing-Reviewing and Editing; Mengyue Yu M.D., PhD.: Supervision, Writing-Reviewing and

Competing interest

The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgment

This work was supported by National Natural Science Foundation of China (81670415).

Disclosure

The authors have no conflicts of interest to disclose.

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