Introduction
Previous studies have consistently demonstrated that coronary artery bypass grafting (CABG) is a prevalent treatment for multi-vessel coronary artery disease (CAD) and left main lesions. However, it’s important to note that while CABG can improve immediate outcomes, it may also hasten the progression of primary coronary atherosclerosis in some patients. This progression can lead to the formation of new chronic total occlusions (CTOs) in as many as 50% of the native coronary arteries post-surgery. Notably, patients who develop new native coronary artery occlusions frequently exhibit recurrent symptoms and adverse cardiovascular events that necessitate subsequent revascularization procedures. In fact, when compared with the initial CABG, repeat CABG procedures tend to yield poorer clinical outcomes, and the percutaneous coronary intervention (PCI) using saphenous vein grafts also shows a higher failure rate. For these challenging cases, PCI targeting the native artery CTO is increasingly favored as the optimal revascularization strategy. Although earlier studies indicate that the success rates of CTO-PCI in patients with history of CABG are lower, this group also experiences a heightened incidence of adverse events, underscoring the critical need to identify patients at an elevated risk for poor outcomes following PCI.
Despite its significance, the long-term prognostic implications of CTO-PCI in patients previously subjected to CABG are not widely understood, particularly in relation to the potential predictive role of the systemic immune-inflammation index (SII) for these high-risk patients. This study sets out to explore the hypothesis that SII may serve as a predictive marker for major adverse cardiovascular events (MACE) in patients with CTO who have previously undergone CABG.
Methods: Subjects
The clinical characteristics, including demographic data and medical histories, were meticulously collected at the time of patient enrollment. Blood samples were promptly drawn from the peripheral veins upon admission to the hospital. Comprehensive laboratory evaluations included a multitude of biomarkers: total white blood cell counts, neutrophil and lymphocyte status, platelet counts, high-sensitivity C-reactive protein (Hs-CRP), hemoglobin levels, cholesterol profiles, brain natriuretic peptide (BNP), D-dimer, and serum creatinine levels. These measurements were conducted at a certified clinical laboratory according to rigorous standard protocols.
The SII was calculated using the formula: total peripheral platelets count (P) multiplied by the neutrophil-to-lymphocyte ratio (N/L), resulting in the expression SII = P × N/L ratio × 109/L. Additionally, both the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were measured contemporaneously.
Angiography
Success during the procedural phase was defined by the successful revascularization of the CTO lesion, which is further quantified using established scoring systems: the PROGRESS CTO score focuses on various complexities like proximal cap ambiguity and the absence of interventional collaterals, while the J-CTO score evaluates parameters such as stump passivation and lesion calcification. Both the PROGRESS and J-CTO scoring systems serve as essential tools for assessing the complexity associated with CTO lesions.
Outcomes
For the evaluation of outcomes, patients included in the study were followed up through a combination of telephone communications, digital medical histories, and outpatient services. The primary endpoint of the study was the composite measure of MACE, encompassing all-cause mortality, nonfatal myocardial infarction, and any unplanned revascularization necessary after the initial procedure. The definition of myocardial infarction adhered to the fourth universal classification guidelines. Unplanned repeated revascularization is characterized by any unexpected PCI or CABG mandated post-surgery.
Statistical Analysis
Categorical data were represented as numbers and percentages, while continuous data were presented either as mean ± standard deviation (SD) or median and interquartile ranges (IQR). The Kolmogorov–Smirnov test was employed to assess data normality. For continuous data comparison, the Student’s T test was used for parameters that fit the parametric model, and the Mann–Whitney U-test for non-parametric variables. Categorical data comparisons utilized the chi-square test and, where necessary, Fisher’s exact test.
In order to account for baseline discrepancies and reduce statistical bias, a probability score matching (PSM) was performed at a 1:1 nearest neighbor matching ratio with a tolerance margin of 0.02. Key variables included in the PSM encompassed age, sex, body mass index (BMI), and smoking status.
The Kaplan–Meier method facilitated the comparative analysis of prognosis and event-free survival across different SII groupings, with the Log-rank test employed for significance assessments. Furthermore, multivariable Cox regression analyses were initiated to identify independent predictors of MACE occurrence, using a stepwise regression approach based on p-value criteria.
The efficacy of various inflammatory markers, including WBC, NLR, PLR, Hs-CRP, and SII, in predicting MACE was assessed through receiver-operating characteristic (ROC) curve analysis. Additionally, a four-knots restricted cubic spline (RCS) analysis was utilized to investigate potential correlational patterns between SII levels and MACE risk. All statistical analyses were conducted with IBM SPSS Statistics 24.0 and R 4.4.
Results: Baseline Characteristics
A total of 3,107 patients diagnosed with CTO were initially assessed, with 337 patients meeting the study’s inclusion criteria. Following probability score matching, a cohort of 335 pairs of patients with and without history of CABG was established. Impressively, the SII values for patients with a history of CABG were significantly elevated compared to those without prior CABG, with median values noted at 570.10 (444.60, 814.12) versus 519.65 (446.86, 565.84), respectively.
Gender distribution revealed that male participants comprised a considerable 76.4% of the population studied, with a mean age of 66 years (ranging from 59 to 70 years). When examining demographic data, medical histories indicated statistically significant differences in the prevalence of hypertension and diabetes mellitus between the two groups. In systematic blood laboratory evaluations, individuals with a history of CABG exhibited higher initial levels of WBC, neutrophil counts, platelet counts, BNP, and D-dimer at the time of admission. Additionally, when evaluating cardiac function through echocardiographic analysis, patients who had previously undergone CABG demonstrated reduced left ventricular ejection fraction (LVEF). Angiographic results also indicated that prior CABG patients had higher J-CTO and PROGRESS scores compared to their counterparts without prior CABG.
Follow-Up and Clinical Outcomes
As part of routine follow-up, patients were engaged either through telephone calls, electronic medical systems, or outpatient clinic visits, facilitating the collection of outcome data over time. This data highlighted the clinical outcomes, emphasizing the continuum and differences between patients who had undergone CABG versus those who had not.
Discussion
This study articulates a crucial finding: CTO-PCI procedures among patients with prior CABG demonstrate inferior success rates and a heightened incidence of MACE compared to patients lacking such surgical history. Notably, this research is pioneering in assessing the correlation between plasma levels of SII and patient outcomes following CABG procedures. The study’s results reveal significantly elevated SII levels in patients with past CABG compared to those without such intervention. Furthermore, a higher SII level is indicative of an independent predictor for the recurrence of adverse cardiovascular events following PCI in CTO patients previously treated with CABG. Importantly, the SII presents as a superior indicator for predicting MACE compared to traditional inflammatory markers.
Managing patients who have previously undergone CABG presents significant clinical challenges. These patients frequently exhibit numerous comorbidities, as well as complications stemming from graft failures, which can complicate the re-intervention of the native coronary artery. Indeed, many such cases are associated with older age, extensive comorbid conditions, and intricate coronary pathology. The alarming trend shows that nearly half of all CABG patients undergoing coronary angiography ultimately receive a diagnosis of a new coronary CTO, largely attributed to the accelerated atherosclerotic process impacting the native arteries post-bypass surgery. The data further corroborate existing literature, which indicates a notable decrease in symptom-free patients following surgical intervention.
Limitations
Conclusion
The dataset analyzed during this study is accessible from the corresponding author upon reasonable request. The study adhered to the ethical guidelines of the Declaration of Helsinki and attained approval from the Ethics Committee of Beijing An-Zhen Hospital at Capital Medical University. Informed consent was acquired from all patients before participation.
Acknowledgment
Gratitude is expressed to all those who contributed to the writing and structuring of this manuscript.
Funding
This research was supported through the National Natural Science Fund of China under grant numbers 82200441, 81970291, and 82170344.
Disclosure
The authors declare no potential conflicts of interest.
The Systemic Immune-Inflammation Index (SII) and Its Impact on Post-CABG Patients
Alright, gather ‘round everyone! Today we’re diving into a topic you might have thought was exclusively reserved for the cardiologists and the nerds among us—but fear not! I’m here to break down the complexities of the systemic immune-inflammation index (SII) and its role in predicting major adverse cardiovascular events (MACE) for patients with chronic total occlusion (CTO) after coronary artery bypass grafting (CABG).
The Problem at Heart
Now, we all know that CABG is like a magic wand for those pesky blocked arteries—except, instead of pulling rabbits out of hats, it can lead to its own set of issues. You see, it turns out that undergoing CABG can accelerate atherosclerosis in native coronary arteries, leading to new chronic total occlusions. Yes, you heard it right, folks—it’s a classic case of “out of the frying pan, into the fire.” Can you believe it? Maybe we should start calling it “Coronary Conundrum Surgery” instead!
The Aim of This Study
The researchers in this study decided to take a closer look at something called the systemic immune-inflammation index (SII) and how it might predict those sneaky cardiovascular incidents lurking in the shadows after a PCI (percutaneous coronary intervention) for CTO patients who’ve been through CABG. Spoiler alert: they discovered something quite interesting!
Methodology: A Peek Behind the Curtain
Now, let’s not get lost in the jargon, but this involved analyzing clinical characteristics and laboratory measurements from a whopping 3107 patients diagnosed with CTO. Out of them, 337 made it into the enchanted circle of this study. Those who had prior CABG had their SII values compared against those who didn’t. Imagine a high-stakes musical chairs game where half the chairs are rigged to break!
Interestingly, the researchers found that patients with prior CABG had a significantly higher SII, and that’s when alarm bells started ringing for MACE. It’s like they discovered that the patients with the higher scores were playing a dangerous game of cardiovascular roulette.
Statistical Shenanigans
Let me give you the lowdown on the statistics—because if we’re going to get to the heart of this issue (pun totally intended), we need to know the odds. The study used tools like Kaplan-Meier survival curves and Cox regression analyses—which sounds like something you’d expect from a top-secret lab rather than a hospital. They even showed that as SII values climbed, so did the risk of MACE. In short, it’s not looking good for those with a bit of SII baggage!
Findings: It’s All in the Numbers!
| Group | Success Rate of CTO-PCI | Incidence of Adverse Events |
|---|---|---|
| Prior CABG Patients | Lower | Higher |
| Without Prior CABG | Higher | Lower |
Surprise, surprise—those who had prior CABG were tripping over more adverse events like a slapstick comedy. Their SII readings painted a gloomy picture, suggesting that CABG doesn’t just grant you a new lease on life; it may also serve as an unwelcome invitation to future complications. Think of it like receiving a bouquet of dead flowers—nice gesture, poor execution!
Conclusion: What’s the Takeaway?
So, what can we conclude from this compelling study? The SII may just become the shiny new tool in our toolkit for predicting post-CABG outcomes. If you find yourself or someone you love in the post-CABG zone, remember that navigating the waters of coronary health can be tricky. Keep an eye on that SII, because it’s more than just digits—it’s a telltale sign of what’s brewing in the heart!
Before we sign off, let’s also remember that discussions like this matter immensely—not just in a lab, but at the hospital where families are worried about their loved ones. So, whether you’re a doctor, patient, or simply curious about cardiovascular outcomes—stay informed and keep a sense of humor through all the statistics. After all, laughter might just be the best medicine!
Aluated how different factors, such as the SII, could predict MACE after revascularization procedures in patients with chronic total occlusion. And guess what? The findings were quite telling!
Key Findings: What Were the Results?
Among the 3,107 initially assessed patients, 335 pairs were ultimately studied after matching on key characteristics such as age, sex, and health conditions. The results were eye-opening: those with a history of CABG presented significantly higher SII values compared to their counterparts without a CABG history. This finding was crucial as it indicated a strong correlation between high SII levels and an increased risk of MACE following PCI.
The researchers emphasized that patients with previous CABG surgeries were at a greater risk for complications after PCI procedures. It seems that once patients have gone under the knife for one heart issue, they might not be out of the woods just yet. The study poignantly highlighted how conditions like hypertension and diabetes were more prevalent in the CABG group, further complicating their clinical journey.
The Bigger Picture: Implications of High SII
So what does this all boil down to? Well, the systemic immune-inflammation index seems to be a promising marker for predicting adverse cardiovascular events in patients following CABG. This means that monitoring SII levels could potentially help clinicians anticipate and mitigate risks in these patients, steering them away from the danger zone. The study encourages clinicians to pay close attention to these inflammatory markers as not all metrics of health are created equal, and some could serve as better indicators of future issues.
Limitations and Future Directions
However, let’s not forget the caveats! Like any research, this study comes with its limitations. As with any statistical analysis, the complexity of heart conditions means there’s still a lot to unravel. More extensive, multicenter studies with long-term follow-ups are suggested to fortify the findings and solidify SII’s role as a key player in cardiac recovery and management post-CABG.
In Conclusion: A New Angle on Cardiovascular Health
What started out as a seemingly niche zone of study—understanding the SII’s impact on patients with CABG—has opened a significant dialogue about improving patient care in cardiology. Having identified a predictive relationship between SII and MACE could lead to better tailored preventive strategies for patients post-CABG. As we unravel the complexities of cardiovascular diseases, discoveries like this remind us of the intricate dance between the immune system and heart health, one that’s worth keeping an eye on!
And that’s a wrap, folks! Remember, knowledge is power, especially when it comes to heart health. Let’s keep this conversation going and advocate for improved monitoring and intervention strategies in our cardiovascular patients!
