Abbreviations
ACS, Acute coronary syndrome
ESRD, End-stage renal disease
HD, Hemodialysis
IDH, Intradialysis hypotension
PD, Peritoneal dialysis
Dear Dr. Yusuf Ziya ŞENER,
I am honored to have the opportunity to reply to letter "Acute Coronary Syndrome in Hemodialysis Patients: A Look from a Broad Perspective". I appreciate the thorough reading and insightful reflections you provided regarding the article entitled "Incidence and Predictors of Acute Coronary Syndrome in Patients on Maintenance Hemodialysis: A Prospective Cohort Study".1
I acknowledged your recommendation to explore wider spectrum of factors influencing acute coronary syndrome (ACS) in hemodialysis (HD) patients. Regrettably, certain variables, including timing of hemodialysis program, pre-dialysis duration of renal diseases, and specific types of glomerulonephritis were not encompassed within our original cohort. Future studies should aim to elucidate these factors comprehensively to refine our understanding of ACS in this population.
Your concern regarding the influence of end-stage renal disease (ESRD) etiology on ACS risk is duly noted. While our study primarily enrolled prevalent HD patients rather than incident cases, we analyzed the association between ACS and comorbid diseases. Patient should be on maintenance hemodialysis for at least 6 months and at enrollment into this study, their median HD duration was 4 years. As your suggestion, we analyzed the association between previous history of glomerulonephritis with ACS. Although an initial observation of a lower ACS risk was noted in univariate analysis, this effect did not persist in multivariate analysis, with diabetic mellitus emerging as the predominant risk factor for ACS.
We appreciate your insight regarding the potential impact of previous peritoneal dialysis (PD) on ACS risk. Owing to the diversities of hemodynamic conditions and metabolic disarrangements between HD and PD, we excluded patients undergoing PD at enrollment.2 A subset of 49 patients with a previous history of PD was identified within our cohort. However, further analysis did not reveal a significant difference in ACS risk among these patients, suggesting that the influence of PD history diminishes following the transition to HD.
We fully agreed with your perspective on intradialysis hypotension (IDH) as a potential confounder in the relationships between vascular access and ACS.3,4 In response, we have identified 318 cases (28% of the cohort) with IDH as a variable in our analysis. While our findings indicated a numerical increase in ACS risk among patients with IDH at baseline, this association did not attain statistical significance, underscoring the complexity of IDH’s role in cardiovascular outcomes among HD patients.
Finally, we have conscientiously integrated your feedback into our analysis, ensuring a comprehensive examination of factors influencing ACS in HD patients, as demonstrated in Table 1. We anticipate that further research will build upon the factors not covered in our cohort, thereby fostering a deeper understanding of the intricate interplay among dialysis modalities, intradialytic dynamics, and ESRD etiologies in shaping cardiovascular outcomes.
Table 1. Univariate and multivariate Cox regression analysis for incident acute coronary syndrome with factors suggested in the letter to the editors.
| Unit of increase | Hazard ratio | 95% CI (lower bond) | 95% CI (upper bond) | p value | |
| Univariate analysis of factors added | |||||
| Glomerulonephritis history | no | 0.56 | 0.32 | 0.96 | 0.04 |
| Peritoneal dialysis history | no | 1.50 | 0.61 | 3.71 | 0.38 |
| Intradialysis hypotension | no | 1.39 | 0.89 | 2.18 | 0.15 |
| Multivariate analysis with factors added | |||||
| Glomerulonephritis history | no | 0.82 | 0.47 | 1.46 | 0.50 |
| Peritoneal dialysis history | no | 1.27 | 0.49 | 3.30 | 0.62 |
| Intradialysis hypotension | no | 1.17 | 0.72 | 1.90 | 0.53 |
| Age > 75 yr | < 65 | 1.96 | 1.12 | 3.42 | 0.02 |
| Smoking | no | 1.70 | 1.01 | 2.88 | 0.05 |
| Diabetes mellitus | no | 1.78 | 1.03 | 3.09 | 0.04 |
| Dyslipidemia | no | 1.61 | 0.98 | 2.65 | 0.06 |
| Arteriovenous graft | fistula | 1.46 | 0.83 | 2.58 | 0.19 |
| Central vein catheter | fistula | 2.04 | 0.93 | 4.45 | 0.07 |
| Prior angioplasty 1-2/yr | 0/yr | 1.88 | 1.09 | 3.25 | 0.02 |
| Prior angioplasty ≥ 3/yr | 0/yr | 2.27 | 1.31 | 3.95 | 0.004 |
| Antiplatelet use | no | 1.78 | 1.04 | 3.04 | 0.03 |
| Beta-blocker use | no | 1.87 | 1.13 | 3.09 | 0.02 |
CI, confidence interval.
Thank you again for your thoughtful insights and reflections. Your contributions have been instrumental in refining the scholarly discourse on ACS in HD patients.
Ju-Yin Hsu and Chih-Cheng Wu
DECLARATION OF CONFLICT OF INTEREST
All the authors declare no conflict of interest.
Acknowledgments
None.
FUNDING/SUPPORTING INSTITUTIONS
None.
REFERENCES
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