Baseline Hemodynamics and Response to Contrast Media During Diagnostic Cardiac Catheterization Predict Adverse Events in Heart Failure Patients

BACKGROUND

Contrast media administered during cardiac catheterization can affect hemodynamic variables. However, little is documented about the effects of contrast on hemodynamics in heart failure patients or the prognostic value of baseline and changes in hemodynamics for predicting subsequent adverse events.

METHODS AND RESULTS

In this prospective study of 150 heart failure patients, we measured hemodynamics at baseline and after administration of iodixanol or iopamidol contrast. One-year Kaplan-Meier estimates of adverse event-free survival (death, heart failure hospitalization, and rehospitalization) were generated, grouping patients by baseline measures of pulmonary capillary wedge pressure (PCWP) and cardiac index (CI), and by changes in those measures after contrast administration. We used Cox proportional hazards modeling to assess sequentially adding baseline PCWP and change in CI to 5 validated risk models (Seattle Heart Failure Score, ESCAPE [Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness], CHARM [Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity], CORONA [Controlled Rosuvastatin Multinational Trial in Heart Failure], and MAGGIC [Meta-Analysis Global Group in Chronic Heart Failure]). Median contrast volume was 109 mL. Both contrast media caused similarly small but statistically significant changes in most hemodynamic variables. There were 39 adverse events (26.0%). Adverse event rates increased using the composite metric of baseline PCWP and change in CI (P<0.01); elevated baseline PCWP and decreased CI after contrast correlated with the poorest prognosis. Adding both baseline PCWP and change in CI to the 5 risk models universally improved their predictive value (P≤0.02).

CONCLUSIONS

In heart failure patients, the administration of contrast causes small but significant changes in hemodynamics. Calculating baseline PCWP with change in CI after contrast predicts adverse events and increases the predictive value of existing models. Patients with elevated baseline PCWP and decreased CI after contrast merit greatest concern.

Iodixanol in Cardioangiography in Patients with Coronary Artery Disease

Iodixanol is a new nonionic, dimeric contrast medium. With the addition of 18 mmol/l Na+ and 0.3 mmol/l Ca++ to iodixanol 320 mg I/ml a plasma-isotonic solution was obtained. The purpose was to evaluate the suitability of iodixanol for use in cardioangiography by determining the diagnostic efficacy, patient tolerability, and cardiac and renal side-effects. Initially, 14 patients with coronary artery disease were examined using iodixanol. A double-blind, randomized study was then performed in 72 patients, comparing iodixanol and iohexol. Serum and urine were sampled before the examination, and one and 2 days after. The diagnostic information was good and the number of adverse events low with iodixanol. The patients reported significantly less of a sensation of warmth following injection of iodixanol than iohexol. Our results also indicate that iodixanol 320 mg I/ml influences renal function to a lesser degree than does iohexol 350 mg I/ml. We therefore conclude that isotonic iodixanol is a safe contrast medium for use in cardioangiography.

Cardiac Effects of Coronary Arteriography with Electrolyte Addition to Iohexol

Electrolyte addition to nonionic contrast media has been suggested to further reduce the incidence of ventricular fibrillation during coronary arteriography. The present study was designed to investigate the effects of adding 30 mM NaCl, 0.9 mM KCl, 0.15 mM CaCl2 and 0.1 mM MgCl2 to iohexol on cardiac electrophysiology and hemodynamics (iohexol + electrolytes = IPE). Contrast media were injected into the left main coronary artery in 9 open-chest, anesthetized dogs before and after induction of acute ischemic heart failure. IPE increased left ventricular inotropy (LV dP/dtmax) with no initial decrease, even during heart failure. During heart failure IPE induced the same hemodynamic effects as iohexol without electrolyte addition. IPE slightly lengthened epicardial monophasic action potential duration before heart failure. We conclude that IPE appears to be well tolerated hemodynamically. The electrophysiologic differences between IPE and iohexol are small when the injection time is not longer than 5 s.

Effect on Cardiac Contractile Force from Addition of Cations and Oxygen to Iohexol

The coronary arteries of the isolated rabbit heart were perfused with different contrast media (CM). The effects on cardiac contractile force (CF) from enriching iohexol solutions with sodium, calcium, potassium, magnesium and oxygen were investigated. The effects were studied during normal and reduced perfusion pressure; the latter was intended to simulate flow conditions distal to proximal stenotic processes of the coronary arteries. By adding the above mentioned cations to iohexol (175 mg I/ml) the smallest influence on CF was found when the CM contained 30 mM NaCl, 0.3 mM CaCl2, 0.9 mM KCl and 0.3 mM MgCl2 and this influence on CF was significantly less than caused by iohexol with 30 mM NaCl (p ≤ 0.01). The influence on CF was further reduced when this iohexol solution was oxygenated with 100% oxygen (p ≤ 0.001). This modified iohexol solution caused a significantly smaller influence on CF than the low-osmotic media iohexol, iopamiro, ioversol and ioxaglate (p ≤ 0.001). Ioxaglate caused the greatest decrease in CF of all the CM (p ≤ 0.001) and to a greater extent during reduced flow than during normal flow (p ≤ 0.01). In conclusion, iohexol enriched with a balanced electrolyte solution and saturated with oxygen had a smaller adverse effect on contractility than iohexol, iopamidol, ioversol and ioxaglate.

Hemodynamic effects of iodixanol and iohexol during ventriculography in patients with compromised left ventricular function

A crossover study was performed to compare the hemodynamic effects of the iso-osmolar contrast agent iodixanol (Visipaque) 320 mg I/ml to those of the low-osmolar iohexol (Omnipaque) 350 mg I/ml. The main hypothesis was that iodixanol and iohexol would affect left ventricular end-diastolic pressure (LVEDP) to different degrees. In 48 patients with reduced cardiac function (mean ejection fraction 33. 4%), one ventricular injection was performed with each contrast medium. Ventricular, aortic and right atrial pressures and heart rate were measured continuously. Cardiac output (using Fick's principle) and systemic vascular resistance were calculated. LVEDP increased with both agents, but significantly less after iodixanol than after iohexol (P < 0.01), also in subgroups of patients in whom baseline LVEDP was severely increased and in whom 3-vessel disease was present. Immediate changes in variables reflecting vasodilatation were similar with both agents. In conclusion, both contrast agents influenced hemodynamics during ventriculography, but iodixanol had significantly less influence on LVEDP than did iohexol.

Preclinical safety assessment of contrast media: predictive value

The purpose of preclinical tests is to identify the potential benefits and risks of new diagnostic or therapeutic products. Regarding iodinated contrast media (CM), LD50 tests were used extensively in the past. However, from both scientific and ethical perspectives, it is today highly relevant to question the use of LD50 tests. Due to species differences and the very high volume of CM needed to kill half of the animals, such tests are not sensitive enough to differentiate between modern nonionic CM. Further, they are not very predictive in terms of human tolerability. In other tests with more relevant end-points than death, overall tolerance to the new dimeric compound iodixanol (Visipaque), representing the latest step in the development of CM, has been shown to be higher than to the nonionic monomers. Clinical experience has shown that the physiological parameters often stay closer to baseline after Visipaque than after administration of conventional CM.

Iodixanol vs iopamidol in intravenous DSA of the abdominal aorta and lower extremity arteries: a comparative phase-III trial

Iodixanol (Visipaque, 320 mgI/ml) was compared with iopamidol (Solutrast, 370 mgI/ml) in a double-blind, randomized, parallel group, intravenous DSA phase-III trial for evaluation of safety and efficacy. A total of 117 patients received iodixanol (n = 60) or iopamidol (n = 57). Diagnostic efficacy was evaluated using categoric and visual analogue scales. Discomfort and adverse events were recorded. A total of 39 patients collected urine up to 72 h after the examination for analysis. Diagnostic efficacy and radiographic density were similar in both groups. Discomfort was milder with iodixanol. The difference between the frequency of adverse events between both groups (iodixanol = 7, iopamidol = 2) was without statistical significance. Creatinine clearance was slightly more affected by iodixanol, whereas the increase in renal excretion of N-acetyl-beta-glucosaminidase (NAG) in the first 24-h collection period after the examination was significantly higher (p < 0.01) with iopamidol. Iodixanol was of equal diagnostic efficacy compared with iopamidol despite its reduced iodine content. Both contrast media are well suited for IV DSA.

Acute hemodynamic effects of intravenous bolus injection of ionic and nonionic magnetic resonance contrast media

RATIONALE AND OBJECTIVES

With the development of fast magnetic resonance (MR) imaging, bolus injection of contrast media is often required. We evaluated the acute hemodynamic effects of intravenous (i.v.) bolus injection of two MR contrast media: ionic gadopentetate dimeglumine and nonionic gadoteridol.

METHODS

Twenty normal rats were anesthetized, and the left ventricular pressure (LVP), right atrial pressure (RAP), peripheral arterial pressure (PAP), positive rate pressure development (dP/dt) of the left ventricle, and heart rate were continuously monitored up to 10 min after bolus injections of 0.1, 0.3, and 0.5 mmol/kg of either media.

RESULTS

Bolus injections of gadopentetate dimeglumine induced temporal reduction of the blood pressure (the peak LVP was -25.0% at 0.5 mmol/kg and -13.2% at 0.3 mmol/kg). At the injected doses of 0.5 and 0.3 mmol/kg, the systolic PAP, mean PAP, and dP/dt were reduced. The lowest peak systolic LVP was observed at around 20 sec after injection. Those suppressed values returned to the control values within 120 sec. Injection of high doses of gadoteridol caused a temporal increase in the peak systolic LVP (9.2% at 0.5 mmol/kg and 7.4% at 0.3 mmol/kg), systolic PAP, and dP/dt. Approximately 15 sec after injection, the highest peak systolic LVP was observed, and within 30 sec the value normalized. With both ionic and nonionic contrast media, a dose of 0.1 mmol/kg did not cause significant changes in hemodynamics.

CONCLUSION

In normal rats, bolus i.v. injection of high-dose gadopentetate dimeglumine has negative hemodynamic effects; gadoteridol produces mild positive effects.

Cardioangiography and the hemodynamic effects of iodixanol

Patient safety should be in focus when using contrast media (CM) in diagnostic and interventional cardiac procedures. Side-effects that occur during cardioangiography due to hemodynamic effects of CM include direct effects on the heart, effects on the systemic and pulmonary circulation, and effects on the blood volume. Although not a totally inert solution, iodixanol (Visipaque) has less pronounced direct inotropic effects on the heart than have other CM; its vasodilatory effects on peripheral arteries are smaller, and the increase in blood volume is smaller after administering iodixanol than after other CM. Thus, iodixanol represents a further step forward in terms of reducing side-effects during contrast-enhanced diagnostic and interventional cardiac procedures.

Cardiac electrophysiology, arrhythmogenic mechanisms and roentgen contrast media

Contrast media (CM) affect normal cardiac electrophysiology when injected into the coronary arteries. High-osmolality CM cause more pronounced electrophysiological effects than do low-osmolality CM. Further, both high- and low-osmolality ionic CM have more pronounced effects than the nonionic CM. The CM-induced electrophysiological effects involve regional disturbances of depolarization and repolarization, thereby causing disturbances of impulse conduction as well as dispersion of refractoriness. Recent experimental studies have demonstrated that the addition of sodium or a balanced electrolyte supplement to nonionic CM reduces the risk of ventricular fibrillation (VF), particularly when the CM is injected in a wedged catheter situation. The reduced risk of VF may be due to the small and transient lengthening of repolarization seen in the CM-perfused area of the myocardium. Iodixanol, which is an isotonic nonionic dimer supplemented with NaCl and CaCl(2), is as well tolerated as iohexol during free coronary flow. However, when flow is restricted, such as when CM is injected through a wedged catheter, the risk of VF is less with iodixanol than with iopamidol, iohexol and ioxaglate.

Cardiac effects of iodixanol compared to those of other nonionic and ionic contrast media on the isolated rat heart

This study was designed to compare the cardiac electrophysiology and mechanical effects of iodixanol to those of iotrolan, iopromide, ioxaglate and diatrizoate. Two consecutive injections of contrast media (CM) (0.3 g I/kg and 0.9 g I/kg b.w.) were given to spontaneously beating, Langendorff-perfused rat hearts. CM were given as a single, short-lasting bolus injection (i.e. over 2 and 5 s). Changes in aortic pressure, left ventricular pressures and ECG were continuously recorded during constant volume perfusion. The nonionic CM had less pronounced effects on aortic pressure than had the ionic media. The peak rate of isovolumetric contraction (LV dP/dt(max)) was slightly decreased by iodixanol and iotrolan, slightly more decreased by iopromide and markedly decreased by ioxaglate and diatrizoate. Similarly, the peak rate of pressure decline (LV dP/dt (min)) was only slightly decreased by iodixanol and iotrolan. Also, the 2 nonionic dimers had the smallest effects on the left ventricular end diastolic pressure (LVEDP) and heart rate. Ioxaglate lengthened the PQ-interval, but less so than diatrizoate. THe QT-interval was only slightly lengthened by iodixanol and iotrolan, as compared to the lenghthening caused by iopromide, ioxaglate and diatrizoate. Single ventricular extrasystoles were seen in all groups. Extrasystoles up to 3 coupled beats were registered after ioxaglate and diatrizoate. No episodes of ventricular fibrillation occurred with any CM. In conclusion, the nonionic dimers, and in particular iodixanol, induce only minor changes in cardiac function, whereas the ionic dimer ioxaglate and the ionic monomer diatrizoate induce pronounced effects.

Cardiac hemodynamic effects of iodixanol, iopamidol, and ioxaglate following left coronary injections in anesthetized dogs

RATIONALE AND OBJECTIVES

Iodixanol, a dimeric, nonionic X-ray contrast medium, has been formulated at 320 mg iodine per milliliter and supplemented with Na+, Ca2+, and Cl- to produce an osmolality that approximates that of plasma. We compared the effects of left main coronary artery injections of iodixanol, ioxaglate, and iopamidol on cardiac mechanical function in dogs.

METHODS

Six mixed-breed dogs were anesthetized and prepared for recordings for electrocardiogram, aortic and left ventricular pressures, and the first derivative of left ventricular pressure, dP/dt. The test solutions and saline were injected into the left coronary artery in a randomized order. The series of four injections were repeated three times in each animal for a total of 12 injections per dog.

RESULTS

Iodixanol caused significantly lower (p < .05) reduction in peak left ventricular pressure (-1.7 +/- 0.9% vs -0.7 +/- 2.0%), in diastolic aortic pressure (-1.3 +/- 1.1% vs -9 +/- 1.3%), and in left ventricular dP/dt (0.3 +/- 1.3% vs -13.2 +/- 2.4%) than did ioxaglate. Iodixanol also produced smaller cardiovascular effects than did iopamidol, but the differences were not statistically significant. Injections of both iopamidol and ioxaglate caused significant decreases from baseline parameter values; however, the changes with iodixanol were not significant.

CONCLUSION

The isotonic formulation of iodixanol caused smaller cardiovascular hemodynamic effects than did iopamidol and ioxaglate and may offer increased safety in patients with severe cardiac disease.

Iodixanol, a new isosmotic nonionic contrast agent compared with iohexol in cardiac angiography

Iodixanol, a new ratio 6 nonionic iodinated contrast agent with an osmolality equal to serum, was compared with iohexol in a randomized, double-blind, parallel study. Two hundred patients undergoing elective diagnostic cardiac angiography were randomized to iodixanol (n = 101) or iohexol (n = 99). There were no differences noted between the 2 agents in the mean changes in systolic or diastolic blood pressure or heart rate during or immediately after any angiography. However, significantly more patients had a decrease in diastolic blood pressure of > 20 mm Hg during left coronary angiography with iodixanol. The only significant differences in any electrophysiologic parameter were slightly more PR prolongation during left coronary angiography with iodixanol and more ST-segment depression with iohexol during coronary angiography. Neither was clinically significant. Injection-associated discomfort occurred with both agents, but more patients experienced moderate to severe discomfort with iohexol (52%) than with iodixanol (17%) (p < 0.001). Only 1 potentially serious adverse event, ventricular fibrillation with iohexol, was considered related to contrast, and there were no differences noted between the agents. Overall, angiographic quality was equal with all angiograms being assessed as good or excellent in both groups (p = 0.885). In this low-risk population undergoing cardiac angiography, iodixanol is safe and effective without clinically important differences from iohexol. Additional studies in patients at high risk for complications should help further define the role of iodixanol in cardiac angiography.