With the continuous advances of imaging technology, iodine contrast medium have been widely used in clinical diagnostic techniques, such as CT, commonly used for CT angiography and CT perfusion.The structure of iodine contrast medium used currently in clinical is a benzenic ring carrying three iodine ions, that is, one iodine ion is replaced in the 1, 3, 5 position of the benzenic ring, and the 2, 4, 6 position can bind three side chains. According to the lonization state in solution, they can be divided into ionic and non-ionic contrast agents. {1}As for non-ionic contrast agents, the non-ionic hydrophilic hydroxyl group is distributed around the benzene ring, shielding the hydrophobic iodophenyl group in it, thereby increasing the water solubility of the compound and reducing its toxicitye side chains, which together form a triiodobenzene ring derivative. Based on the size of plasma osmotic concentration, iodine contrast medium can be divided into high-osmolal, low-osmolal, and iso-osmolal ICM. The osmotic concentration of high-osmolal ICM is more than five times that of plasma osmotic; low-osmolal ICM is about two-three times that of plasma osmotic concentration (600–800 mmol/L); the osmotic concentration of iso-osmolal ICM is roughly the same as that of plasma osmotic concentration (about 290 mmol/L). the same iodine content, the dimer iodine contrast medium exhibit fewer molecule number, lower penetration concentration, and higher viscosity than the haplotype iodine contrast medium{2} According to the updated 2011 ESUR Contrast Media Safety Committee guidelines, clinical CI-AKI is defined as the notion that without the influence of surgery, nephrotoxic drugs, and other causes, renal function is impaired, and Scr content is increased by 0.5 mg/dL (44.2 μmol/L) or more than 25% compared with the basic value within 72 h after intravascular injection of iodine contrast medium.[3] Although the KDIGO used the CI-AKI in 2012, it is defined as an absolute increase of 26.5 μmol/L in Scr content compared to baseline within 48 h after intravascular administration of iodine contrast medium, or a relative increase of more than 50% within 7 days, without the influence of factors such as surgery or nephrotoxic drugs [4]. The specialist consensus for CI-AKI in China indicates that exclusion of other factors, Scr levels increased by 25% or 0.5 mg/dL compared to the baseline value after use of contrast agents [5] The most common definition of CIN today is an increase of 25% or more, or an absolute increase of 0.5 mg/dl or more in serum creatinine from baseline value, at 48–72 h following the exposure to CM. The first 24 h post-exposure appear to be crucial in the development of CIN. A study of the trajectory of serum creatinine elevation in the randomized Prevention of Radiocontrast Induced Nelphropathy Clinical Evaluation trial indicated that in 80% of CIN cases serum creatinine started to rise within the first 24h post-CM exposure, and nearly all patients who progressed to serious renal failure (one requiring either nephrology consultation or dialysis) had a rise in serum creatinine within this time frame. An overall incidence of CIN in the general population is reported to be 0.6–2.3% .The incidence of CI-AKI in patients with chronic kidney disease is up to 40%. Because approximately 13% of hospitalized patients are likely to be permanently dependent on dialysis, CI- AKI is also associated with long-term kidney failure, hos- pitalization dialysis need, and overall mortality (7-31%) [6]. Among patients recovering from AKI, one-third of them will develop CKD within 2–5 years [7]. Although only 0.06% of patients require renal replace- ment therapy due to decreased renal function [8, 9], approximately 25–30% of CI-AKI will progress to chronic renal failure [10]; The average length of hospital stay and socio-economic burden of CI-AKI increase by 5–10 times [11]. This is especially true in patients with cardiovascular pathology. In the interventional cardiology registry from Mayo Clinic including 7586 patients, the incidence of CIN was 3.3% .In a smaller study from William Beaumont Hospital, among 1826 patients treated with PCI, CIN occurred in 14.5% of the cases. .Dialysis as a result of CIN in these two series was required in 0.7 and 0.3%, respectively. The risk of CIN is especially high (19%) in the setting of primary PCI for acute myocardial infarction.

A cross-sectional study was conducted in the Department of Cardiology, Jawaharlal Nehru Medical College, KAHER, Belagavi, a multispecialty teaching hospital from January 2024 to June 2025. Study design This was a prospective observational study involving a total of 300 patients who are undergoing PCI(Elective and Emergency) was done creatinine at admission and after 48hours after PCI and prsdicted the risk of developing CIN with modified Mehran score in comparision to Meharan score. Data collection procedure: The present study will be cross sectional in design which is conducted at Cardiology Department of Jawarhalal Nehru Medicl Colloege, KAHER the multispeciality teaching hospital. The patients will be seen (Primary Researcher) first in ICCU where diagnosis of AMI will be established based on the criteria of MI and who undergo PCI and calculate the risk of CIN All the patients fulfilling the inclusion criteria and willing to participate, will be included in the study.Informed consent will be obtained. Further they will be subjected to a detailed history and predesigned proforma. Data processing and analysis/statistical analysis: Since the study is of observational study the plan of analysis will be as follows.For the continuous quantitative variables mean and standard deviation will be calculated. For the purpose of comparison, if the data is divided into two groups with respect to certain qualitative characteristic, the continuous variables will be compared using suitable tools of statistics like student’s unpaired t test. The pre and post treatment measures will be compared using student’s paired t test.If required, ROC analysis, sensitivity, specificity, cut off value etc., will be calculated.Discrete variables will be represented by median. The categorical data will be expressed in terms of rates, ratios and percentages. The association between the outcome, clinical and demographic characteristics will be tested using Chi-square test, test of proportion or Fisher’s exact test.For discrete variables nonparametric tests will be used.Apart from the above suitable tools like ANOVA, correlation, regression etc., will be used according to the need.Suitable graphs will be used to depict the comparison. For all the tests the value of p less than 5% (0.05) will be considered significant

Sociodemographic data of the study participants

The sociodemographic characteristics of the study participants are summarized in Table 1. A total of 300 study participants based on inclusion and exclusion criteria were included in the study. Majority of the study participants were between the age group of 51-70 constituting to 61.3% (n=184), followed by 20.3% (n=61) in 31-50 years, 18% (n=54) in 71-90 years and 0.3% (n=1) in 18-30 years group. Among the study participants, 70.3% (n=211) were male and 29.7% (n=89) were female.

Clinical Profile of the study participants

The prevalence of diabetes, hypertension, congestive heart failure, hypotension and anemia among the study participants were 46% (n=138), 48.3% (n=145), 1.7% (n=5), 2.3% (n=7) and 6.3% (n=19) respectively. Summarized in Table 2. Among study participants, 1.3% (n=4) had intra-aortic balloon pump (IABP). . The contrast media volume among study participants were 225 (n=66) in 0-100 ml, 53.3% (n=160) in 100-200 ml, 22.3% (n=67) in 200-300 ml and 2.3% (n=7) in 300-400 ml, Table 3 and Table 4. Among the study participants, 86.3% (n=259) were on statins, Table 5. Trans radial route was reported in 21.7% (n=65) and trans femoral route was reported in 78.3% (n=235) of study participants. The contrast volume to eGFR ratio is less than 1 in 19.3% (n=58), between 1-2 in 41.7% (n=125), greater than 2 and less than 3.7 in 32.3% (n=97) and greater than 3.7 in 6.7% (n=20) study participants. The Mehran score of low, moderate, high and very high among study participants were 84% (n=252), 12% (n=36), 3.3% (n=10) and 0.7% (n=2) respectively. The modified Mehran score of low, moderate, high and very high among study participants were 0 (0%), 34.7% (n=104), 31.3% (n=94) and 34% (n=102) respectively. Comparison of Modified Mehran and Mehran Score is Summarized in Table 6 and Table 7

Table 1. Sociodemographic profile of study participants (N = 300)

Table 2. Clinical Profile of the Study Population

Table 3.Comparision of contrast volume to Mehran score

Table 4.Comparision of contrast volume to Modified Mehran score

Table 5.Comparision of statin to Modified Mehran score

Table 6.Modified Mehran Score Distribution by Original Mehran Score (Column %)

Table 7. Original Mehran Score Distribution by Modified Mehran Score (Row %)

A total of 300 study participants were included in this prospective observational study based on inclusion and exclusion criteria. Majority of the study participants were between the age group of 51-70 constituting to 61.3% (n=184), followed by 20.3% (n=61) in 31-50 years, 18% (n=54) in 71-90 years and 0.3% (n=1) in 18-30 years group. A total of 891 patients (522 men, 369 women; mean age, 6413 years) were included in this study  according to Fabio A. Sgura, et al Among the study participants, 70.3% (n=211) were male  29.7% (n=89) were female. Among the 2487 patients, there were 1898 males and 589 females, with an average age of 64.30±11.13 years. Ying Guo, MD et al. The prevalence in Meharan score of diabetes, hypertension, congestive heart failure, hypotension and anemia among the study participants were 46% (n=138), 48.3% (n=145), 1.7% (n=5), 2.3% (n=7) and 6.3% (n=19) respectively. Diabetes Mellitus (DM): Present in 41.3% of low, but much higher in moderate (69.4%), high (70%), and all very high (100%) score groups. The association was statistically significant (p = 0.002).Hypertension (HTN): Fairly evenly distributed (46.8% in low vs. 52.8% moderate vs. 70% high, 50% very high). The association was not statistically significant (p = 0.494).Congestive Heart Failure (CHF): Absent in low scores, but present in 2.8% of moderate, 20% of high, and all very high (100%) scores. Strongly significant (p = 0.000).Intra-aortic Balloon Pump (IABP): Absent in low scores, but used in 5.6% of moderate, 10% of high, and 50% of very high scores. Also highly significant (p = 0.000).Diabetes: Strongly associated with higher Modified Mehran scores. Present in 74.5% of patients in the Very High group, compared to only 13.5% in the Moderate group (p = 0.000).Hypertension (HTN): Also significantly linked to higher risk, with 58.8% prevalence in the Very High group versus 33.7% in the Moderate group (p = 0.001).Congestive Heart Failure (CHF): Absent in moderate/high groups but appears in 4.9% of the Very High group (p = 0.007).Intra-aortic Balloon Pump (IABP) use: Not seen in lower-risk groups but required in 3.9% of patients with Very High Modified Mehran score (p = 0.020).Among study participants, 1.3% (n=4) had intra-aortic balloon pump (IABP). The contrast media volume among study participants were 225 (n=66) in 0-100 ml, 53.3% (n=160) in 100-200 ml, 22.3% (n=67) in 200-300 ml and 2.3% (n=7) in 300-400 ml. The majority of patients across all contrast volume categories fell into the low Mehran score group (76–86%).Moderate scores were more frequent with 200–300 ml contrast use (19.4%) compared to other groups (7–14%).High and very high scores were rare overall, with only scattered cases in the 0–200 ml contrast group and none at higher contrast volumes (>300 ml).The association between contrast volume and Mehran score distribution was not statistically significant (p = 0.597). Among the study participants, 86.3% (n=259) were on statins. Across all Mehran score categories (low to very high), the majority of patients were on statins (85.7%–100%).Only a small proportion of patients without statins appeared in the low (14.3%), moderate (11.1%), and high (10%) score groups.None of the very high score patients were statin-free.The association between statin use and Mehran score distribution was not statistically significant (p = 0.870).Trans radial route was reported in 21.7% (n=65) and trans femoral route was reported in 78.3% (n=235) of study participants. In Meharan score, Transradial access accounted for 23.4% of low, but less frequent in higher score groups (11.1% moderate, 10% high, 50% very high).Transfemoral access was predominant across all categories (76.6% of low, 88.9% of moderate, 90% of high, 50% of very high).No statistically significant association was observed (p = 0.207).Trans radial access: More common in lower-risk groups, with 45.2% in Moderate, but only 5.9% in the Very High group (p = 0.000).Transfemoral access: Dominates in higher-risk groups, seen in 94.1% of Very High patients compared to 54.8% in the Moderate group.The contrast volume to eGFR ratio is less than 1 in 19.3% (n=58), between 1-2 in 41.7% (n=125), greater than 2 and less than 3.7 in 32.3% (n=97) and greater than 3.7 in 6.7% (n=20) study participants. The Mehran score of low, moderate, high and very high among study participants were 84% (n=252), 12% (n=36), 3.3% (n=10) and 0.7% (n=2) respectively. The modified Mehran score of low, moderate, high and very high among study participants were 0 (0%), 34.7% (n=104), 31.3% (n=94) and 34% (n=102) respectively.Patients with ratio <1 were mostly in the low-risk group (21.4% low, 11.1% moderate, none high/very high).Those with ratio 1–2 formed the largest group (46.8% low, with a small but increasing share in moderate to very high).Ratio >2 patients had a higher representation in moderate (47.2%) and high (50%) risk groups.Extreme ratio >3.7–3.9 clustered strongly in moderate (30.6%), high (30%), and very high (50%) categories.The association was statistically significant (p < 0.001).This analysis highlights a strong correlation between contrast volume normalized to renal function (eGFR) and Mehran risk score. Patients with higher contrast/eGFR ratios were disproportionately represented in moderate-to-very high risk categories, underscoring the role of contrast dose relative to renal clearance as a key determinant of CIN risk.While absolute contrast volume is important, this ratio better captures individual patient vulnerability, especially in those with impaired renal reserve.Most patients classified as Moderate or High by the modified score fall almost entirely into the Low risk category of the original Mehran score.The Very High modified score group shows a spread: ~57% remain Low, ~31% shift to Moderate, and ~12% distribute into High/Very High by the original score.This indicates that the Modified Mehran Score reclassifies higher-risk patients more aggressively, while the original Mehran Score tends to under-classify risk.Almost all patients with High or Very High original scores are classified as Very High by the modified score.Patients with Low original scores are spread across Moderate, High, and Very High modified categories, highlighting some reclassification.

Our study showed a significant positive results with modified mehran score for better prediction of CIN and its complications.Most patients classified as Moderate or High by the modified score fall almost entirely into the Low risk category of the original Mehran score.The Very High modified score group shows a spread: ~57% remain Low, ~31% shift to Moderate, and ~12% distribute into High/Very High by the original score.This indicates that the Modified Mehran Score reclassifies higher-risk patients more aggressively, while the original Mehran Score tends to under-classify risk.Almost all patients with High or Very High original scores are classified as Very High by the modified score.Patients with Low original scores are spread across Moderate, High, and Very High modified categories, highlighting some reclassificationThis analysis highlights a strong correlation between contrast volume normalized to renal function (eGFR) and Mehran risk score. Patients with higher contrast/eGFR ratios were disproportionately represented in moderate-to-very high risk categories, underscoring the role of contrast dose relative to renal clearance as a key determinant of CIN risk.While absolute contrast volume is important, this ratio better captures individual patient vulnerability, especially in those with impaired renal reserve. The contrast/eGFR ratio should be routinely monitored in PCI procedures.Stricter thresholds (e.g., keeping ratio <2) may help minimize CIN risk, especially in high-risk patients.This supports personalized contrast dosing strategies rather than fixed maximum volume limits.Integrating this ratio into procedural planning can improve nephroprotection and align with risk stratification tools like the Mehran score. ETHICAL CONSIDERATION The study protocol was reviewed and approved by the Institutional Ethics Committee of Jawaharlal Nehru Medical College, KAHER (Approval No.MDC/JNMCIEC/21)All procedures were conducted in accordance with the ethical principles. Eligible participants were informed in detail about the study’s purpose, objectives, procedures, potential risks, and benefits in a language they understood. Written informed consent was obtained from all participants prior to enrolment. The study did not impose any financial burden on the participants in any form. Those identified as having depression were counselled empathetically and referred to the Department of Psychiatry for further evaluation and appropriate management, ensuring timely clinical care. FUNDING: This research did not receive any specific grant from funding agencies in, the public, commercial, or not-for-profit sectors. CONFLICTS OF INTEREST: The author(s) declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

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