To the Editor,
We read with great interest the article by Chen et al. [Citation1] indicating that cholecystectomy is negatively associated with acute myocardial infarction (AMI) among gallbladder stones patients, and that the potential protective effect is not only short-term but lasts for years. We appreciate the authors for collecting data from a countrywide database for this retrospective cohort study. The authors also present the quantitative information about the numbers need to treat (N = 1000) regarding this issue, providing the reader with a more concrete concept. However, we would like to underline some key points:
First, researchers identified patients with gallstone disease as the study group based only on the International Classification of Diseases, Ninth revision, Clinical Modification codes. We would suggest that researchers provide additional validation data, such as positive prediction rates or cite additional references, to improve the accuracy of gallstone diagnosis in their studies.
Second, the authors applied propensity score matching to address measurable confounders, including age, gender, region of residence, occupation, and comorbidities associated with the primary outcome AMI. They also thoughtfully excluded patients with a history of coronary artery disease, a major risk factor for AMI at baseline, rather than allowing them to enter the Cox regression model for a clearer analysis. However, patients with end stage kidney disease and endometriosis are known to be at risk of AMI [Citation2–4]. We suggest that the authors to include these covariates in the analysis to make the results more robust.
Third, in Table 4, the researchers performed the subgroup analysis stratified by follow-up years after cholecystectomy to examine the risk of subsequent AMI in both groups. Since not all patients with cholelithiasis undergo cholecystectomy at the time of diagnosis, and gallstone disease tends to recur, which may leave the patient in a state of chronic inflammation that interferes with subsequent AMI [Citation5]. We would like to know if the length of time from diagnosis of gallbladder stone to cholecystectomy has any effect on the risk of AMI.
We are convinced by the authors’ conclusions and look forward to their response.
Disclosure of financial/other conflicts of interest
The authors have no relevant conflicts of interest to disclose. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.
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References
- Chen CH, Lin CL, Kao CH. The effect of cholecystectomy on the risk of acute myocardial infarction in patients with gallbladder stones. Postgrad Med. 2021 Mar;133(2):209–216.
- Hong JS, Kang HC, Lee SH, et al. Long-term trend in the incidence of acute myocardial infarction in Korea: 1997-2007. Korean Circ J. 2009 Nov;39(11):467–476.
- Sun CY, Li CY, Sung JM, et al. A comparison of the risk of acute myocardial infarction in patients receiving hemodialysis and peritoneal dialysis: a population-based, propensity score-matched cohort study. Atherosclerosis. 2020 Aug;307:130–138.
- Wei CH, Chang R, Wan YH, et al. Endometriosis and new-onset coronary artery disease in Taiwan: a nationwide population-based study. Front Med (Lausanne). 2021;8:619664.
- Zheng Y, Xu M, Li Y, et al. Gallstones and risk of coronary heart disease: prospective analysis of 270 000 men and women from 3 US cohorts and meta-analysis. Arterioscler Thromb Vasc Biol. 2016 Sep;36(9):1997–2003.