Daijiworld Media Network - London
London, Nov 7: Elevated levels of lipoprotein(a) are associated with more than twice the risk of recurrent myocardial infarction (heart attack) among patients with Type 2 diabetes who have previously experienced acute coronary syndrome (ACS) or undergone percutaneous coronary intervention (PCI), according to a systematic review and meta-analysis involving 7,887 patients.
The findings highlight the potential role of lipoprotein(a) in contributing to residual cardiovascular risk even after patients receive secondary preventive treatment. However, its association with repeat coronary revascularisation remains uncertain.
Researchers conducted a systematic review and meta-analysis to examine whether elevated lipoprotein(a) concentrations were associated with recurrent heart attacks and repeat coronary revascularisation among diabetic patients with a history of ACS or PCI.
The study population comprised patients at an increased risk of subsequent ischaemic cardiovascular events. Following a systematic search of three electronic databases, researchers included seven observational studies involving 7,887 patients in the analysis.
The eligible studies reported hazard ratios for recurrent cardiovascular outcomes, which were pooled using random-effects models. The primary objective was to determine whether lipoprotein(a), a known contributor to residual cardiovascular risk, could provide additional prognostic information in this high-risk population.
The analysis found that patients with elevated lipoprotein(a) had a significantly higher risk of recurrent myocardial infarction compared with those without elevated levels. The pooled hazard ratio stood at 2.17, with a 95 per cent confidence interval of 1.02–4.62.
However, considerable variation was observed across the studies, with statistical heterogeneity recorded at I²=75 per cent.
For repeat coronary revascularisation, elevated lipoprotein(a) was associated with a numerically higher risk, with a pooled hazard ratio of 1.68 and a 95 per cent confidence interval of 0.79–3.57. However, the association was not statistically significant. Heterogeneity for this outcome was also substantial at I²=78 per cent.
The findings indicate that elevated lipoprotein(a) is associated with an increased risk of recurrent heart attacks in patients with Type 2 diabetes following ACS or PCI, while evidence linking it to subsequent coronary revascularisation remains inconclusive.
The researchers said the results highlight lipoprotein(a) as a potential marker of residual cardiovascular risk in diabetic patients even after an initial cardiac event or intervention.
However, they pointed out several limitations, including the observational nature of the studies, substantial differences in the reported findings and limited evidence concerning repeat revascularisation.
The analysis therefore could not establish a direct cause-and-effect relationship between elevated lipoprotein(a) levels and recurrent cardiovascular events.
Overall, the findings support further investigation into the role of lipoprotein(a) measurement in cardiovascular risk assessment following acute coronary syndrome. Additional research is required to establish its prognostic value and determine how it could help guide secondary prevention strategies among patients with Type 2 diabetes.