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Determinants of stenosis compliance during coronary angioplasty
300A
JACC Vol. 17. No. 2 February 1991:3WA
ABSTRACTS
Wednesday, March 6, 1991 oster Displayed: 2:00 M Author Present: 2:OOP all F, West Concourse The Pathophysiology of Balloon Angioplasty METHODOLOGICALPROBLEMS RELATED TO THE ASSESSMENTOF RECOILAND BALLOON-ARTERYRATtO mker RM Hemm $enno J Rensing, Bradley H Strauss, Ma& van den Brand, Pim de Fey& Harry Suryapransta,Patrkk Serruys. Thoraxcenter, Rotterdam,The Netherbnds. Overstretching(balloon-arteryratio)of thedilated vesselwall is known to result in more acute and late complicationsfollowing balloon Coronaryangioplasty. Elasticrecoil of the dilated vesselwall hes a negatlve effect on the immediate result of the angioplastyprocedure.The balloon (baJ)isused as scalingdevice to measurethe balloon-arteryratio (bar) and recoil. For correct use of the balloonas a scalingdevice one assumesa uniformlyinflated balloon. However this latter assumption has never been properly adressed. In this study, 431 lesions(122RCA,202 IAD, 107LCX)and balloonswere quantitativelyanalyzed usingan automatededge detectiontechnique.Single identicalviewswere used for analysisof the lesion and contrast filled balloon at maximumpressure.The balloonwas analysedover Its entirelength (mean 16.5 ? 3.9 mm) excludingthe tapered proximaland distal parts. The pressureused varied between 3 and 16 atmosphere(atm)(mean8.3 f 2.6 atm).To standardizefor vasomotion,nltmtes were givenintmcoronatypre and post angioplasty.Four dlfferent anglogmphlc parametersof the balloon were measured. Beside a minimal and maximal dlameter,a mean balloon diameter is measuredas the average dismetar over the entirelengthof the balloon.The referenceballoon diameter was definedas the d&meterat the site of the minimalwidth of the balloon using an interpolated method. Recoilwas defined as the ratlo between ballwn diameter minus the obstructiond&meter post-PTCAand the referencediameterof the segment.Bar was determinedby the relationbetweenthe balloon diameterand the reference dlameterpre-PTCAof the segment. reCOil :2.37 0.21 Eil mlnWl bst &meter (mm) 1:13 :2.96 rnax~r,~ibai dhmeter (mm) K :2.64 1.00 mean bal diameter (mm) referencebsl diameter(mm) :2.75 oki 1.05
REFLEX VASOMOTOR RESPONSE OF DIFFERENT CORONARY ARTERY SEGMENTS BEFORE
B~~CARD~A~
mssan El-Tamimi, Graham Davies, Filippo Crea, David Hackett, Piyamitr Sritara, Oliver Bertrand, Attilio Maseri. Cardiovascular Unit, Hammersmith Hospital, London, UK To study the effect of acute segmental damage on the vasomotor response of epicardial coronary arteries to reflex sympathetic stimulation, coronary arterigraphy was performed in the basal state and during the cold pressortest immediately beforeand 5 minutes. 4 hours and 8 days after PTCA in 10 patients with single vessel stenosis and on no vasoactive drugs. Quantitative arteriographic measurement of minimum vessel diameter within the dilated (PTCA) segment, the distal segment and a segmentof a branch not subjected to PTCA (control) was performed. During the cold pressortest before PTCA there was a decreasein diameter of both the PTCA and the distal segment in all patients (~~0.008 vs basal),but the diameter of the control segmentincreasedin 5 patients :cnd decreasedin the other 5. At 4 hours the diameter of the PTCA segment increased in all patients (~~0.002 vs basal) and that of the distal segment increased in 6 patients and decreased in the other 4 : however, the control segment decreased in all patients (pcO.001 vs basal). The segmentalpattern of responseat 6 days was identical to that before PTCA (pcO.uOlvs basal, for both PTCA and distal segment1. Therefore, PTCA causesan acute alteration of the response to reflex sympathetic stimulation which extends throughout the epicardial coronary arterial tree and has resolved by 8 day?. The altered resporlse appears to be unrelated to arteriographic evidence of atherosclerosis and. is suggestiveof a neurohumoral change.
Conclusion: The balloon is not uniformlyInRatedalong its entire length with a maximum dtfference of 0.59 mm with a mean pressure of 8.3 atm. consequently,the extent of recoil and bar is highly dependent on the selected balloon diametervariablewith a maximalvariation of 100%for recoil and 25% variationin the ballwn-artery mtio.
INCREASEDVO ANGIOPLAST’Y PROCEDURE Knowledgeof the radial force requiredto dil 318a given coronary stenosismay be useful in the selectionof wropriate balloon materialsand inflation strategies. Sequentialinflation pressuresof 2, 3,4,6,8, and 10 atm were applied to 114 stenoses in 89 patients undergoingPEA. At each pressurethe minimal lesion diameterwas quantitativelyderived from analysis of the pattern of indentationupon the balloon. A compliance index (Cl) was computed as the pressure at which 75% of the maximum stenosis expansion had been achieved;hence, larger values representless compliant lesions. We evaluatedthe relation betweenCl and 13 different angiographic variablesthat might impact the force requiredfor dilation, including lesion calcification,length, eccentricity,location, appearance, angulation,percent stenosis, and prior dilations. The degree of eccentricitywas found to be the strongestpredictor @ c 0.02), with eccentriclesions requiring less dilating force (Cl = 3.85 f 2.35 atm ;33] ys 5.56 f 2.64 atm for concentriclesions). Additionally,the locationof the lesion within the arterial tree correlated significantly with Cl @ < 0.03). LAD stenoseswere generally more compliant (3.93 f 2.44 atm) than RCA (5.43 f 1.99 atm) or LCx (5.50 f 2.89 atm) lesions. NO other variables,including the presence and severity of calcification,related significantlyto compliance. Thus, inflationcompliancediffers greatly between stenoses, and is greatest in eccentric lesions located in the left anterior descending artery. This knowledgemay help optimize inflation pressures, permittingenhancedefficacy with reduced risks.
CORONARY PLICATED
celin.
d CT’SVersailles. Le
8s measured within 2
JACC Vol. 17. No. 2 February 1991:3WA
ABSTRACTS
Wednesday, March 6, 1991 oster Displayed: 2:00 M Author Present: 2:OOP all F, West Concourse The Pathophysiology of Balloon Angioplasty METHODOLOGICALPROBLEMS RELATED TO THE ASSESSMENTOF RECOILAND BALLOON-ARTERYRATtO mker RM Hemm $enno J Rensing, Bradley H Strauss, Ma& van den Brand, Pim de Fey& Harry Suryapransta,Patrkk Serruys. Thoraxcenter, Rotterdam,The Netherbnds. Overstretching(balloon-arteryratio)of thedilated vesselwall is known to result in more acute and late complicationsfollowing balloon Coronaryangioplasty. Elasticrecoil of the dilated vesselwall hes a negatlve effect on the immediate result of the angioplastyprocedure.The balloon (baJ)isused as scalingdevice to measurethe balloon-arteryratio (bar) and recoil. For correct use of the balloonas a scalingdevice one assumesa uniformlyinflated balloon. However this latter assumption has never been properly adressed. In this study, 431 lesions(122RCA,202 IAD, 107LCX)and balloonswere quantitativelyanalyzed usingan automatededge detectiontechnique.Single identicalviewswere used for analysisof the lesion and contrast filled balloon at maximumpressure.The balloonwas analysedover Its entirelength (mean 16.5 ? 3.9 mm) excludingthe tapered proximaland distal parts. The pressureused varied between 3 and 16 atmosphere(atm)(mean8.3 f 2.6 atm).To standardizefor vasomotion,nltmtes were givenintmcoronatypre and post angioplasty.Four dlfferent anglogmphlc parametersof the balloon were measured. Beside a minimal and maximal dlameter,a mean balloon diameter is measuredas the average dismetar over the entirelengthof the balloon.The referenceballoon diameter was definedas the d&meterat the site of the minimalwidth of the balloon using an interpolated method. Recoilwas defined as the ratlo between ballwn diameter minus the obstructiond&meter post-PTCAand the referencediameterof the segment.Bar was determinedby the relationbetweenthe balloon diameterand the reference dlameterpre-PTCAof the segment. reCOil :2.37 0.21 Eil mlnWl bst &meter (mm) 1:13 :2.96 rnax~r,~ibai dhmeter (mm) K :2.64 1.00 mean bal diameter (mm) referencebsl diameter(mm) :2.75 oki 1.05
REFLEX VASOMOTOR RESPONSE OF DIFFERENT CORONARY ARTERY SEGMENTS BEFORE
B~~CARD~A~
mssan El-Tamimi, Graham Davies, Filippo Crea, David Hackett, Piyamitr Sritara, Oliver Bertrand, Attilio Maseri. Cardiovascular Unit, Hammersmith Hospital, London, UK To study the effect of acute segmental damage on the vasomotor response of epicardial coronary arteries to reflex sympathetic stimulation, coronary arterigraphy was performed in the basal state and during the cold pressortest immediately beforeand 5 minutes. 4 hours and 8 days after PTCA in 10 patients with single vessel stenosis and on no vasoactive drugs. Quantitative arteriographic measurement of minimum vessel diameter within the dilated (PTCA) segment, the distal segment and a segmentof a branch not subjected to PTCA (control) was performed. During the cold pressortest before PTCA there was a decreasein diameter of both the PTCA and the distal segment in all patients (~~0.008 vs basal),but the diameter of the control segmentincreasedin 5 patients :cnd decreasedin the other 5. At 4 hours the diameter of the PTCA segment increased in all patients (~~0.002 vs basal) and that of the distal segment increased in 6 patients and decreased in the other 4 : however, the control segment decreased in all patients (pcO.001 vs basal). The segmentalpattern of responseat 6 days was identical to that before PTCA (pcO.uOlvs basal, for both PTCA and distal segment1. Therefore, PTCA causesan acute alteration of the response to reflex sympathetic stimulation which extends throughout the epicardial coronary arterial tree and has resolved by 8 day?. The altered resporlse appears to be unrelated to arteriographic evidence of atherosclerosis and. is suggestiveof a neurohumoral change.
Conclusion: The balloon is not uniformlyInRatedalong its entire length with a maximum dtfference of 0.59 mm with a mean pressure of 8.3 atm. consequently,the extent of recoil and bar is highly dependent on the selected balloon diametervariablewith a maximalvariation of 100%for recoil and 25% variationin the ballwn-artery mtio.
INCREASEDVO ANGIOPLAST’Y PROCEDURE Knowledgeof the radial force requiredto dil 318a given coronary stenosismay be useful in the selectionof wropriate balloon materialsand inflation strategies. Sequentialinflation pressuresof 2, 3,4,6,8, and 10 atm were applied to 114 stenoses in 89 patients undergoingPEA. At each pressurethe minimal lesion diameterwas quantitativelyderived from analysis of the pattern of indentationupon the balloon. A compliance index (Cl) was computed as the pressure at which 75% of the maximum stenosis expansion had been achieved;hence, larger values representless compliant lesions. We evaluatedthe relation betweenCl and 13 different angiographic variablesthat might impact the force requiredfor dilation, including lesion calcification,length, eccentricity,location, appearance, angulation,percent stenosis, and prior dilations. The degree of eccentricitywas found to be the strongestpredictor @ c 0.02), with eccentriclesions requiring less dilating force (Cl = 3.85 f 2.35 atm ;33] ys 5.56 f 2.64 atm for concentriclesions). Additionally,the locationof the lesion within the arterial tree correlated significantly with Cl @ < 0.03). LAD stenoseswere generally more compliant (3.93 f 2.44 atm) than RCA (5.43 f 1.99 atm) or LCx (5.50 f 2.89 atm) lesions. NO other variables,including the presence and severity of calcification,related significantlyto compliance. Thus, inflationcompliancediffers greatly between stenoses, and is greatest in eccentric lesions located in the left anterior descending artery. This knowledgemay help optimize inflation pressures, permittingenhancedefficacy with reduced risks.
CORONARY PLICATED
celin.
d CT’SVersailles. Le
8s measured within 2