Br Heart J: first published as 10.1136/hrt.51.6.643 on 1 June 1984. Downloaded from Br Heart3J 1984; 51: 643-7 Comparative trial of iohexol 350, a non-ionic contrast medium, with diatrizoate (Urografin 370) in left ventriculography and coronary arteriography I D SULLIVAN, R J WAINWRIGHT, J F REIDY, E SOWTON From the Departments ofCardiology and Radiology, Guy's Hospital, London suMMARY In a prospective double blind randomised study in 25 consecutive patients a conventional ionic contrast medium (Urografin 370) was compared with the new non-ionic medium iohexol 350 (Omnipaque) in left ventriculography and coronary arteriography. In left ventriculography there was a clear patient preference for iohexol by both a visual analogue scale and independent observer assessment. Iohexol also induced a smaller increase in heart rate or decrease in systolic blood pressure than Urografin. In coronary arteriography iohexol resulted in a smaller reduction in heart rate and systolic blood pressure, a smaller maximum increase in RR interval, less prolongation of the PQ and QT intervals and QRS duration, and a lower incidence of induced chest pain, ST segment depression, or T wave deflection. Left ventriculography and coronary arteriography in backs, however, were its instability in aqueous solu- patients investigated because of suspected coronary tion and its very high cost. More recently, stable solu- artery disease carry a low morbidity and very low tions of three different low osmolality contrast media mortality risk.' The left ventriculogram in most have been developed. The ionic mono-acid dimer http://heart.bmj.com/ patients produces pain and heat sensation ofa variable Hexabrix (Guerbet) was found to be associated with degree. The severity of the discomfort appears to be less patient discomfort during left ventriculography related to the degree of induced arteriolar dilatation, than the conventional ionic contrast media but with both of which are related to the osmolality of the con- similar T wave changes during coronary arteriography trast medium used,2 although their precise inter- when compared with Urografin 370 and with more T relation remains uncertain. The impairment of wave changes than Triosil or metrizamide.6 The non- myocardial contractility which occurs after selective ionic compound iopamidol-(Niopam, E Merck Ltd) coronary arteriography is directly related to the achieved greater patient tolerance and a significantly on September 28, 2021 by guest. Protected copyright. osmolality and the chemistry of the contrast medium smaller increase in peripheral arterial blood flow than used, as are the electrocardiographic changes seen as a a conventional ionic contrast medium in lumbar aor- result ofdirect inhibition ofsinoatrial node automatic- tography.7 Its use in a non-randomised open study ity and atrioventricular nodal conductivity and con- has also shown less patient discomfort after left ven- duction delay in distal portions of the Purkinje net- triculography, a smaller decrease in systolic blood work.3 pressure and heart rate, and fewer T wave electrocar- The first non-ionic and low osmolality contrast diographic changes after selective coronary arteriog- medium metrizamide (Amipaque) was produced as raphy.5 long ago as 1972. Clinical studies showed that it was The aim of this study was to compare non-ionic associated with less patient discomfort after left ven- iohexol 350 and the conventional diatrizoate contrast triculography4 and with fewer T wave abnormalities4 medium Urografin 370 in left ventriculography and and less chest pain5 after coronary arteriography when coronary arteriography. Differences between the two compared with ionic contrast media. Its major draw- media in patient tolerance, objective haemodynamic changes after left ventricular angiography, and elec- Requests for reprints to Dr E Sowton, Department of Cardiology, trocardiographic changes were determined after selec- Guy's Hospital, London SEI 9RT. tive coronary arteriography in a prospective double Accepted for publication 12 January 1984 blind randomised crossover trial. 643 Br Heart J: first published as 10.1136/hrt.51.6.643 on 1 June 1984. Downloaded from 644 Sullivan, Wainwright, Reidy, Sowton Patients and methods during, and after each coronary injection. Heart rate and systolic blood pressure were recorded as mean Twenty five consecutive patients undergoing routine values calculated from 10 consecutive cycles before left ventriculography and selective coronary arteriog- and immediately after each injection. PQ, QRS, and raphy for investigation of chest pain were included in QT intervals were measured as the mean of the three the study. Patients with unstable angina, previous highest values from the 10 cycles immediately before coronary artery bypass surgery, or valvular heart dis- and after each injection. The maximum increase in ease were excluded. There were 22 men and three RR interval was also noted. Maximum ST segment women, age range 22-74 (mean 50*7) years. depression measured 0-08 s after the end of the QRS Standard Sones catheterisation techniques were complex and T wave deflection were each considered used. Normal drug treatment was withheld on the day significant if there was a change of at least 0-1 mV of the investigation. Premedication was with 10 mg compared with the preceding rhythm strip. The oral diazepam. A CM5 bipolar electrocardiographic induction of angina-like chest pain with specific coro- rhythm strip was monitored continuously. Two left nary injections was noted. ventricular angiograms were performed in the 300 The same rate of injection and volume of contrast right anterior oblique plane, once with iohexol 350 medium were used for each injection into a particular (Omnipaque, Nyegaard (UK) Ltd), and once with coronary artery. There was a minimum delay of 45 s meglumine and sodium diatrizoate (Urografin 370, between successive coronary injections, longer if the Schering Chemicals Ltd), the sequence being deter- CM5 rhythm strip had not regained its baseline pat- mined randomly. The same volume of contrast tern. medium and rate of injection (35 ml at 8 ml/s) and Catheterisation procedures were all performed by similar catheter position were used in each case. the same operator, and patient subjective responses elicited by a single (different) observer. The only per- VENTRICULOGRAPHY son aware of the sequence of administration of the Patients were warned to expect a "warm feeling" after contrast media was the nurse. The code was not left ventriculography and that they would be asked broken until data collection was complete. Angiog- subsequently to assess this sensation. After the second raphic film quality was independently assessed by left ventricular angiogram subjective patient comparing the matched left ventricular angiograms. responses to each were graded on as: 0, no discomfort; 1, mild heat or pain; 2, moderate heat or pain; 3, STATISTICAL ANALYSIS distress or nausea or both; and 4, vomiting or retching Statistical evaluation of paired data was by Student's http://heart.bmj.com/ or both. Each patient was then asked to grade "dis- paired t test. Differences between proportions were comfort" associated with each of the left ventricular assessed by the x2 method with Yates's correction. angiograms on a 0 (no discomfort) to 100 (intolerable discomfort) visual analogue scale. Heart rate, systolic Results blood pressure, and left ventricular end diastolic pres- sure were measured before each left ventricular All 25 catheterisation procedures were completed angiogram and immediately, one, two, and three without major complications. In one patient the sec- minutes after. There was a delay of 10-15 s in obtain- ond left ventriculogram caused intramyocardial stain- on September 28, 2021 by guest. Protected copyright. ing the "immediate" recordings while the catheter ing with contrast medium; this pair of left ven- was flushed with saline and reconnected to the man- triculograms was excluded from subsequent analysis ometer line. Heart rate was calculated from the mean of patient subjective response. Catheter tip systolic of 10 consecutive cycle lengths and left ventricular blood pressure fell below 80 mm Hg in two patients end diastolic and systolic pressures from the mean of when the right coronary artery was selectively cannu- five consecutive cycle lengths. Left ventricular end lated. As it was not considered safe to leave the cathe- diastolic pressure was measured after the "a" wave, ter tip in situ for prolonged periods changes in systolic all 25 patients being in sinus rhythm. blood pressure after selective right coronary injections in these two patients were excluded from analysis. CORONARY ARTERIOGRAPHY Two selective right coronary artery injections were then given once with each medium, the sequence Table 1 Patients visual analogue assessment (range 0-100) of being determined randomly. After this, two selective discomfort induced by left venticulography using iohexol or Urografin. Values are means +SD left coronary artery injections were given once with each contrast medium, the sequence being reversed. Iohexol Urografin p Catheter blood pressure and the CM5 rhythm strip 33-7±18.1 49.5±23-2 <000l were recorded at a paper speed of 50 mm/s before, Br Heart J: first published as 10.1136/hrt.51.6.643 on 1 June 1984. Downloaded from Comparative trial of iohexol 350 645 20- ]Iohexol visual analogue assessment of the discomfort induced 18- (Table 1) and by observer grading (Figure). On the 16- Urogrcfin visual analogue