Effects of viscosity on power and hand injection of iso-osmolar iodinated contrast media through thin catheters.

BACKGROUND: It can be challenging to achieve adequate vessel opacification during percutaneous coronary interventions when using thin catheters, hand injection, and iso-osmolar contrast media (CM) such as iodixanol (Visipaque™). PURPOSE: To explore these limitations and the possibility to overcome them with iosimenol, a novel CM. MATERIAL AND METHODS: Three X-ray contrast media with different concentrations were used in this study. A series of in vitro experiments established the relationship between injection pressure and flow rate in angiography catheters under various conditions. The experiments were conducted with power and hand injections and included a double-blind evaluation of user perception. RESULTS: By using hand injection, it was generally not possible to reach a maximum injection pressure exceeding 50 psi. The time within which volunteers were able to complete the injections, the area under the pressure-time curve (AUC), and assessment of ease of injection all were in favor of iosimenol compared with iodixanol, especially when using the 4F thin catheter. Within the pressure ranges tested, the power injections demonstrated that the amount of iodine delivered at a fixed pressure was strongly related to viscosity but unrelated to iodine concentration. CONCLUSION: There are substantial limitations to the amount of iodine that can be delivered through thin catheters by hand injection when iso-osmolar CM with high viscosity is used. The only viable solution, besides increasing the injection pressure, is to use a CM with lower viscosity, since the cost of increasing the concentration, in terms of increased viscosity and consequent reduction in flow, is too high. Iosimenol, an iso-osmolar CM with lower viscosity than iodixanol might therefore be a better alternative when thinner catheters are preferred, especially when the radial artery is used as the access site.

Iso-osmolar vs low-osmolar contrast agents for coronary optical coherence tomography: a blinded prospective randomized controlled study.

BACKGROUND: The impact of contrast type on coronary optical coherence tomography (OCT) imaging has received limited research. METHODS: We conducted a blinded, prospective, single-center, randomized, controlled crossover study comparing iso-osmolar contrast media (IOCM) with low-osmolar contrast media (LOCM) in patients undergoing clinically indicated coronary OCT imaging. Patients were randomly assigned to undergo OCT imaging with either IOCM or LOCM as the initial contrast medium. Following a washout period, a second run of OCT imaging of the same coronary vessel was performed using the other contrast medium. RESULTS: A total of 62 patients were randomized to IOCM first (n = 31) or LOCM first (n = 31). Mean patient age was 65.9 ± 11.2 years and 74.2% were male, with high prevalence of dyslipidemia (82.3%) and prior myocardial infarction (41.9%). Percutaneous coronary intervention was performed in 60 cases (96.8%) and the left anterior descending artery was the most common target vessel (53.3%). The contrast volume used for OCT imaging was similar for IOCM and LOCM (8.0 [6.9, 9.0] mL vs 8.0 [6.7, 9.0] mL; P = .89), as was the length of clear OCT images (70.0 [62.8, 74.0] mm for IOCM vs 70.0 [64.0, 74.0] mm for LOCM; P = .65). Electrocardiographic changes were observed in 11 runs with IOCM (ventricular repolarization changes in 9 runs and premature ventricular contractions [PVCs] in 2 runs) vs 12 runs with LOCM (ventricular repolarization changes in 9 runs and PVCs in 3 runs). CONCLUSIONS: The use of IOCM in coronary OCT is associated with similar contrast volume and clear imaging length when compared with LOCM.

Symptomatic Intracranial Hemorrhage after Mechanical Thrombectomy - the Difference between Iso-Osmolar and Low-Osmolar Contrast Media.

Objective: Symptomatic intracranial hemorrhage (SICH) after mechanical thrombectomy (MT) is generally considered a critical complication. Hemorrhagic transformation after ischemic stroke has also been associated with contrast media administration. The objective of our study was to evaluate correlations between contrast media type and incidence of SICH after MT. Methods: Ninety-three consecutive patients (41 men; mean age, 80.2 years; range, 44-98 years) underwent MT reperfusion (expanded thrombolysis in cerebral infarction score, 2a-3) for acute large-vessel occlusion ischemic stroke within 8 h after symptom onset between April 2020 and July 2023 were retrospectively reviewed. Correlations between contrast media type (iso-osmolar or low-osmolar medium) and incidence of SICH were assessed. Results: Contrast media were iso-osmolar in 60 cases or low-osmolar in 33 cases. The overall incidence of SICH was 5.5%. The frequency of SICH was significantly lower in the iso-osmolar group (1.7%) than in the low-osmolar group (12.1%; P = 0.033). Conclusion: Iso-osmolar contrast media was associated with a lower incidence of SICH compared with low-osmolar contrast media in patients after MT.

Contrast-induced nephropathy in a patient with type 2 diabetes and coronary artery disease: a case report.

Contrast-induced nephropathy (CIN) is the impairment of kidney function defined as a serum creatinine increase of 25% or 44 µmol/L compared with baseline, usually occurring 24 to 48 hours after the use of intravenous contrast. Important risk factors for CIN include female sex, advanced age (>65 years), type 2 diabetes (T2D), kidney disease, advanced heart failure, and intravascular volume depletion. We herein present a male patient with T2D, moderately reduced renal function, no albuminuria, and a positive echocardiography stress test. He underwent percutaneous coronary intervention (PCI), and two drug-eluting stents (in the left anterior descending coronary artery) and three bare-metal stents (in the right coronary artery) were implanted. Despite adequate rehydration (0.9% intravenous NaCl with 8.4% sodium bicarbonate) before and after the procedures, he developed irreversible kidney injury after coronary angiography and PCI. This case report demonstrates the unpredictable clinical course of CIN. Patients with T2D are at high risk for the occurrence of CIN, so careful clinical assessment is recommended with global renal functional reserve evaluation.

The effect of major adverse renal cardiovascular event (MARCE) incidence, procedure volume, and unit cost on the hospital savings resulting from contrast media use in inpatient angioplasty.

OBJECTIVE: To determine the net economic impact of switching from low-osmolar contrast media (LOCM) to iso-osmolar contrast media (IOCM; iodixanol) in patients undergoing inpatient coronary or peripheral angioplasty in the United States (US). METHODS: A budget impact model (BIM) was developed from a hospital perspective. Nationally representative procedural and contrast media prevalence rates, along with MARCE (major adverse renal cardiovascular event) incidence and episode-related cost data were derived from Premier Hospital Data (October 2014 to September 2015). A previously estimated relative risk reduction in MARCE associated with IOCM usage (9.3%) was applied. The higher cost of IOCM was included when calculating the net impact estimates at the aggregate, hospital type, and per hospital levels. One-way (±25%) and probabilistic sensitivity analyses identified the model's most important inputs. RESULTS: Based on weighted analysis, 513,882 US inpatient angioplasties and 35,610 MARCE cases were estimated annually. Switching to an "IOCM only" strategy from a "LOCM only" strategy increases contrast media cost, but prevents 2,900 MARCE events. The annual budget impact was an estimated saving of $30.71 million, aggregated across all US hospitals, $6,316 per hospital, or $60 per procedure. Net savings were maintained across all univariate sensitivity analyses. While MARCE/event-free cost differential was the most important factor driving total net savings for hospitals in the Northeast and West, procedural volume was important in the Midwest and rural locations. CONCLUSIONS: Switching to an "IOCM only" strategy from a "LOCM only" approach yields substantial net global savings to hospitals, both at the national level and within hospital sub-groups. Hospital administrators should maintain awareness of the factors that are likely to be more influential for their hospital and recognize that purchasing on the basis of lower contrast media cost may result in higher overall costs for patients undergoing inpatient angioplasty.