- Email: [email protected]
Restenosis after successful emergency coronary angioplasty for acute myocardial infarction; comparison with elective angioplasty
ELSEVIER.
l”tPmatio”al Journal of Cardioloey 47 (suppt.) , ,994, w-s54
Restenosis after successful emergency coronary ang for acute myocardial infarction: comparison w elective angioplasty Yoshikazu
Hiasa*, Hiroyuku Fuzinaga, Tatsuya Wada, Rhuzi Ohtani, Kohichi Kishi, Tsukasa Aihara
We investigated the initial and late restenosis rate after successful emergency coronary angioplasty in 64 patients with acute myocardial infarction. and compared these results with those of 100 patients ( I IO lesions) who had succe&d on an elective basis. The majority of the baseline clinical and angiographic variables were similar in the myocardial infarction and elective groups. The restenosis rate at month was high in patients undergoing emergency angiophwty for acute myocardial infarction (23 vs. 12%). At 3-6 months, the angiographic restenosis rate was low for the infarction group (26 vs. 37%). The overall rester&s rate was similar in the infarction and elective groups (39 vs. 40%). Lesion regression after coronary angioplasty was more frequent in the infarction then in the elcctivc angioplasty group (27 vs. 14%. P < 0.05). These findings suggest that considering the high restenosis rate at I moath and the lower. but still 20% or mare, rate et 3-6 months, a follow-up angiogmphy should be perfanned both prior to discharge and at 3-6 months after the procedure. in patients with acute myccardial infarction. angioplasty
Key
I
wordx
Tbrombus
Acute
myocardial
infarction:
Emergency
coronary
angmplasty;
Restenoais;
Follow-up
angiography;
formation
1. htroductiw Emergency coronary angioplasty of the infarctrelated vessel has been performed with increasing frequency, both directly and after thrombolysis.
This emergency angioplasty is an effective method of achieving myocardial reperfusion, though this
efficacyis limitedby restenosis rate after successful have not been
coronary
and factors emergency
restenosis.
related coronary
to
The
restenosis angioplasty
adequately characterized. No previous study has ,compared the restenosis rates on serial angiography after successful emergency and elective angioplasty. The purpose of this report is to investigate the initial and long-term restenosis rates after successfid emergency angioplasty for acute myocardiil infarction, and to compare these
results with those of patients who had successful angiopia&y on an elective basis. Moreover, we have attempted to determine the optimal timing of anglographic restudy. 2 Materials and methods
WC reviewed the records of 64 consecutive patients with acute myocardial infarction in whom successful emergency coronary angioplasty, with or without antecedent thrombolytic therapy, was attempted in our ho&tat between January 1990 and July 1993. The diagnosis of acute myocardial infarction was established by: (1) chest pain consistent with ongoing myocardiai isehemia pemisting for more than 30 mio; (2) at least 1 mm ST-segment ebatioo in two or mom leads in B 124ead electrocardiogram; (3) angiographic demonstration of subtotal or total occhtsion of the infarct-related artery: and (4) post-angioplasty confirmation of myocardial infarction by elevated serum cmatine kinase. All patients received inter veotional therapy within 6 h of acute myocardial infarction. Forty-eight patients were treated with direct angioplasty, and 16 received thrombolytic therapy followed by coronary angioplasty. ‘Ihe choice of treatment was made by the attending physicians. As a control group, we chose 100 consecutive patients (110 treated lesions) who had been selected for elective percutanwus transluminal cotonaty angioplasty (PTCA) because of angiographic evidence of significant coronary lesions ( > 75% luminal narrowing).
Emergency cardiac catheterization was p formed via the femoral artery. The mean time from the onset of chest pain to the angioplasty \\‘a8 4.2 $: 1.5 h. All patients received 2CCtl U of heparin at the time of the arterial access and an additional 5000 U just before angioplasty. Aspirin (497 tag) and dipyridamole (10 mg) were also int~venousiy ~1ninisIered before angjop~sty. In the majority of patients a 0.018 inch guide wire and over-the-wire bedloon catheter were used.
Typic&y, two to three itttlations lasting 120-180 s were performed across the lesion with a pressure suflicient to achieve balloon expansion. Coronary angioplasty was only performed for the infarct-related artery. Treated lesions were observed by serial angiogmphy in at least two projections for a minimum of 10 mitt after the last suilicient dilatation. Patients received intravenous hepacin and isosorbide dir&rate, and oral aspirin (81 m&hay), nitrate, and calcium antagonist aher the pmcedure. If recurrent chest pain accompanied by 1 mm or more ST-elevation or depression in the infarct-related territory occurred, the patients nndetwent emergency angiogmphy and, if necessary, additional angiopiasty. Coronary angioplasty suecess was defined as a~o~p~ sucse~s (a t&dual stenosis of c 50% after angiophtsty) with the absence of ctinieal evidence of ischamia until hoepital discharge. Elective coronary angioplasty was also performed by way of the femoral approach using the standard technique. The angioplasty procedure was considered successful if the residual stenosis was less than 5CPAand no major procedural complications occurred. In the majority of patients who were treated with emergency or elective angioplasty, follow-up angiography to identify restenosis was performed at I month and 3-6 months after the pxxedure. Restenosis was defined as a residnd stenosis of r&Y?? of the htminal diameter, at the time of tbe follow-up amdogrsphy.
Data are reported as means&SD. The tmpaired Student’s t-test was used to assess the differences in continuous variables between patients receiving emergency or elective PTCA. The x2-test was used for categorical variables. A Pvalue of < 0.05 was considered significant. 3. Remlm The baseline clinical and angiographic characteristics of the studv oatients are shown in Table 1. The mean age. seX,‘location of coronary angiopiasty hsions, frequency of coronary dissection
Table
I
Clinical and angiographit characwistics of the acute myocardial infarction and the eleefive coronary angiaplarty groups
pmcedures and the majority of the coronary risk factors were similar in the two gro”+. The history of diabetes and 3-vessel disease were more frequently sze” in the elective than in the emergency angioplasty group. The folkw-up angiographii restenosis rates of the acute myocardial infarction and the elective coronary angioplasty groups are show” in Fig. 1. A total of 64 conxcutive patients were successfully treated by emergency angioplasty, of whom 47 underwent a pre-discharge angiography about 1 month after the initial angioplasty. Of these, 11 patients (23%) showed restenosis. The remaining 36 patients, as well as the 17 without a pre-discharge study, were followed up 3-6 months after aRer
the intervention, and four and IO of these patients, respectively, showed restenosis. I” total, 14 (26%) of the 53 patients had coronary restmosis at 3-6 months. The uvemll an@ogia?hic restenosis rate was 39% (25 out of 64 patients). The angiographic restenosis rate of the elective angioplasty patients is also shown in Fig. 1. A follow-up coronary angiography, about 1 month after the procedure, was obtained in 52 of the 1IO lesions with suuzssful elective angioplasty. Restenosis was documented in six of these lesions (12%). Nineteen of the remaining 46 treated lesions. which were free of early restenosis, and 19 of the 58 lesions without a” early follow-up study, had rcstenosis at the late follow-up study (the r&en&s rate at 3-6 months was 37”/.). Of the total I10 lesions, 44 (40%) had restenosis. The comparison of the restenosls rates between the acute myocardial infarction group and the elective angioplasty group is show” in Fig. 2. Changes in the residual diameter stenosis hetwee” the emergency and the elective angioplasty groups are shown in Fig. 3. A tendency, which was not signiticant, for less residual stenosis was observed inxnediatcly after elective angioplasty (28 + 11% in elective vs. 31* 12% in emergency angioplasty; P < 0.10). At 1 month follow-up, the diameter stenosis did not diier between the cmergency and the elective angioplasty groups. At 3-6 months follow-up, signikantly less stenosis was found in the emergency angioplasty group (48 f 20 YS.41 + 19%; P < 0.02).
”
1 Month
3-6
Months
Overall
Fig. 2. Comparison or mtenosis rates betweeo emergency and elective coronary angiophiy
The frequency of lesion regression after angioplasty is shown in Fig. 4. Decreases of 10% and more in residual luminal stenosis on follow-up angiography were recognized in 17 (27%) of the 64 patients undergoing emergency angioplasty and in 15 (14%) of the 110 patients receiving elective
groups. n.s., not signilicwd
angioplasty. These incidences were signifkant (P < 0.05). Between the period immediately after the procedure and the I month follow-up. improvement in residual stenosis was found in 15 (88%) of the 17 emergency patients with lesion regression, in contrast to five (33%) of the I5 elective patients.
I_ PCO. 02
20 10 n
Emergency
Elective
Fig. 4. Frequeacyof lesionregressionafter successfulwgi* puny. 4. Dkenssion The results of the present study indicate that the overall rate of eariy pius iate restenosis was similar for patients in the infarction and the elective angioplasty groups (39 vs. 46%, respectively), white early restenosis is common in patients undergoing emergency angioplasty for acute myocardial infarction. Early angiograpbic restenosis or reoeclusion at the angioplasty site before hospital diiharge, oozurs in 631% of patients with initially successful angioplasty [I]. Early (about 1 month follow-up) restenosis after elective angioplasty was, however, low in a recent study using repeat angiography or staged coronary angioplasty 121. Our data are in good agreement with these observations. There is no clear explanation for the higher incidence of early restenosis after successful entergency angioplssty, though several factors may exist. Firstly, in emergency angioplasty of a total or subtotal infarct-related artery, information on the lesion (for example, degree and morphology of the underlying stenosis) is not adequate, therefore sutfkient balloon-size or Sation pressure
may be unsuitable. Secondly, the majority of infarct-related lesions are associated with a large thrombus that may be difficult to compress by balloon diiatation and may be adherent to the lesions. Thirdly, there may be redevelopment of thrombus at the site of a previously thrombosed atrial segment, as a result of persistent activation of platelets and residual fibrin deposits. Our data, in which lesion regression after angioplasty was found more frequently in patients undergoing emergency angiopfasty than in patients undergoing elective angioplasty, may reflect thrombus formation. The rate of long-term angiographic restenosis after successful emergency angioplasty with or without thrombolysis, has been reported in wera1 small series of patients and it ranges from 7-45% [1,3-S]. The majority of physicians generally did not perform routine long-term follow-up angiography in the absence of reCurrent symp tams. The late restenosis rate in the present study is 26%. which is a moderate level among published rates. Previous studies, examining angiographic follow-up after successful angioplasty on an elective basis, have found Lhat 17-40% of patients develop coronary restenosis [6-X]. These studies, however, failed to standardize the time of angiographic study. Nobuyoshi et al. [2] reported that the actuarial restenosis rate was 12.7% at 1 month and 43.0% at 3 months and that restenosis rarely occurred beyond 3 months. In OUTstudy, resteoosis was observed in 12% of 52 lesions at 1 month, and in 37% of 104 lesions at 3-6 months. These findings show a low late restenosis rate in patients treated with emergency an@oplasty for acu!e myocardial infarction. In conclusion, OUTresults suggest that in the early stage after angioplasty, restenosis or reocclusion in patients undergoing successful emergency angioplasty is relatively high, while being relatively lower in the late stage than in those treated with elective angioplasty. The rcawn for the high early restenosis rate in patients with acute myocardial infarction is related to some combination of intimal dissection, recurrent formation of thrombus and iotraplaque hemorrhage. Considering this higher restenosis rate at 1 month and
the
lower,
but
still more
than
20Y0, rate
at 3-6
months, a follow-up angiography should be performed both prior to discharge and at 3-6 months after the procedure, in patients with acute myocardial infarction.
l”tPmatio”al Journal of Cardioloey 47 (suppt.) , ,994, w-s54
Restenosis after successful emergency coronary ang for acute myocardial infarction: comparison w elective angioplasty Yoshikazu
Hiasa*, Hiroyuku Fuzinaga, Tatsuya Wada, Rhuzi Ohtani, Kohichi Kishi, Tsukasa Aihara
We investigated the initial and late restenosis rate after successful emergency coronary angioplasty in 64 patients with acute myocardial infarction. and compared these results with those of 100 patients ( I IO lesions) who had succe&d on an elective basis. The majority of the baseline clinical and angiographic variables were similar in the myocardial infarction and elective groups. The restenosis rate at month was high in patients undergoing emergency angiophwty for acute myocardial infarction (23 vs. 12%). At 3-6 months, the angiographic restenosis rate was low for the infarction group (26 vs. 37%). The overall rester&s rate was similar in the infarction and elective groups (39 vs. 40%). Lesion regression after coronary angioplasty was more frequent in the infarction then in the elcctivc angioplasty group (27 vs. 14%. P < 0.05). These findings suggest that considering the high restenosis rate at I moath and the lower. but still 20% or mare, rate et 3-6 months, a follow-up angiogmphy should be perfanned both prior to discharge and at 3-6 months after the procedure. in patients with acute myccardial infarction. angioplasty
Key
I
wordx
Tbrombus
Acute
myocardial
infarction:
Emergency
coronary
angmplasty;
Restenoais;
Follow-up
angiography;
formation
1. htroductiw Emergency coronary angioplasty of the infarctrelated vessel has been performed with increasing frequency, both directly and after thrombolysis.
This emergency angioplasty is an effective method of achieving myocardial reperfusion, though this
efficacyis limitedby restenosis rate after successful have not been
coronary
and factors emergency
restenosis.
related coronary
to
The
restenosis angioplasty
adequately characterized. No previous study has ,compared the restenosis rates on serial angiography after successful emergency and elective angioplasty. The purpose of this report is to investigate the initial and long-term restenosis rates after successfid emergency angioplasty for acute myocardiil infarction, and to compare these
results with those of patients who had successful angiopia&y on an elective basis. Moreover, we have attempted to determine the optimal timing of anglographic restudy. 2 Materials and methods
WC reviewed the records of 64 consecutive patients with acute myocardial infarction in whom successful emergency coronary angioplasty, with or without antecedent thrombolytic therapy, was attempted in our ho&tat between January 1990 and July 1993. The diagnosis of acute myocardial infarction was established by: (1) chest pain consistent with ongoing myocardiai isehemia pemisting for more than 30 mio; (2) at least 1 mm ST-segment ebatioo in two or mom leads in B 124ead electrocardiogram; (3) angiographic demonstration of subtotal or total occhtsion of the infarct-related artery: and (4) post-angioplasty confirmation of myocardial infarction by elevated serum cmatine kinase. All patients received inter veotional therapy within 6 h of acute myocardial infarction. Forty-eight patients were treated with direct angioplasty, and 16 received thrombolytic therapy followed by coronary angioplasty. ‘Ihe choice of treatment was made by the attending physicians. As a control group, we chose 100 consecutive patients (110 treated lesions) who had been selected for elective percutanwus transluminal cotonaty angioplasty (PTCA) because of angiographic evidence of significant coronary lesions ( > 75% luminal narrowing).
Emergency cardiac catheterization was p formed via the femoral artery. The mean time from the onset of chest pain to the angioplasty \\‘a8 4.2 $: 1.5 h. All patients received 2CCtl U of heparin at the time of the arterial access and an additional 5000 U just before angioplasty. Aspirin (497 tag) and dipyridamole (10 mg) were also int~venousiy ~1ninisIered before angjop~sty. In the majority of patients a 0.018 inch guide wire and over-the-wire bedloon catheter were used.
Typic&y, two to three itttlations lasting 120-180 s were performed across the lesion with a pressure suflicient to achieve balloon expansion. Coronary angioplasty was only performed for the infarct-related artery. Treated lesions were observed by serial angiogmphy in at least two projections for a minimum of 10 mitt after the last suilicient dilatation. Patients received intravenous hepacin and isosorbide dir&rate, and oral aspirin (81 m&hay), nitrate, and calcium antagonist aher the pmcedure. If recurrent chest pain accompanied by 1 mm or more ST-elevation or depression in the infarct-related territory occurred, the patients nndetwent emergency angiogmphy and, if necessary, additional angiopiasty. Coronary angioplasty suecess was defined as a~o~p~ sucse~s (a t&dual stenosis of c 50% after angiophtsty) with the absence of ctinieal evidence of ischamia until hoepital discharge. Elective coronary angioplasty was also performed by way of the femoral approach using the standard technique. The angioplasty procedure was considered successful if the residual stenosis was less than 5CPAand no major procedural complications occurred. In the majority of patients who were treated with emergency or elective angioplasty, follow-up angiography to identify restenosis was performed at I month and 3-6 months after the pxxedure. Restenosis was defined as a residnd stenosis of r&Y?? of the htminal diameter, at the time of tbe follow-up amdogrsphy.
Data are reported as means&SD. The tmpaired Student’s t-test was used to assess the differences in continuous variables between patients receiving emergency or elective PTCA. The x2-test was used for categorical variables. A Pvalue of < 0.05 was considered significant. 3. Remlm The baseline clinical and angiographic characteristics of the studv oatients are shown in Table 1. The mean age. seX,‘location of coronary angiopiasty hsions, frequency of coronary dissection
Table
I
Clinical and angiographit characwistics of the acute myocardial infarction and the eleefive coronary angiaplarty groups
pmcedures and the majority of the coronary risk factors were similar in the two gro”+. The history of diabetes and 3-vessel disease were more frequently sze” in the elective than in the emergency angioplasty group. The folkw-up angiographii restenosis rates of the acute myocardial infarction and the elective coronary angioplasty groups are show” in Fig. 1. A total of 64 conxcutive patients were successfully treated by emergency angioplasty, of whom 47 underwent a pre-discharge angiography about 1 month after the initial angioplasty. Of these, 11 patients (23%) showed restenosis. The remaining 36 patients, as well as the 17 without a pre-discharge study, were followed up 3-6 months after aRer
the intervention, and four and IO of these patients, respectively, showed restenosis. I” total, 14 (26%) of the 53 patients had coronary restmosis at 3-6 months. The uvemll an@ogia?hic restenosis rate was 39% (25 out of 64 patients). The angiographic restenosis rate of the elective angioplasty patients is also shown in Fig. 1. A follow-up coronary angiography, about 1 month after the procedure, was obtained in 52 of the 1IO lesions with suuzssful elective angioplasty. Restenosis was documented in six of these lesions (12%). Nineteen of the remaining 46 treated lesions. which were free of early restenosis, and 19 of the 58 lesions without a” early follow-up study, had rcstenosis at the late follow-up study (the r&en&s rate at 3-6 months was 37”/.). Of the total I10 lesions, 44 (40%) had restenosis. The comparison of the restenosls rates between the acute myocardial infarction group and the elective angioplasty group is show” in Fig. 2. Changes in the residual diameter stenosis hetwee” the emergency and the elective angioplasty groups are shown in Fig. 3. A tendency, which was not signiticant, for less residual stenosis was observed inxnediatcly after elective angioplasty (28 + 11% in elective vs. 31* 12% in emergency angioplasty; P < 0.10). At 1 month follow-up, the diameter stenosis did not diier between the cmergency and the elective angioplasty groups. At 3-6 months follow-up, signikantly less stenosis was found in the emergency angioplasty group (48 f 20 YS.41 + 19%; P < 0.02).
”
1 Month
3-6
Months
Overall
Fig. 2. Comparison or mtenosis rates betweeo emergency and elective coronary angiophiy
The frequency of lesion regression after angioplasty is shown in Fig. 4. Decreases of 10% and more in residual luminal stenosis on follow-up angiography were recognized in 17 (27%) of the 64 patients undergoing emergency angioplasty and in 15 (14%) of the 110 patients receiving elective
groups. n.s., not signilicwd
angioplasty. These incidences were signifkant (P < 0.05). Between the period immediately after the procedure and the I month follow-up. improvement in residual stenosis was found in 15 (88%) of the 17 emergency patients with lesion regression, in contrast to five (33%) of the I5 elective patients.
I_ PCO. 02
20 10 n
Emergency
Elective
Fig. 4. Frequeacyof lesionregressionafter successfulwgi* puny. 4. Dkenssion The results of the present study indicate that the overall rate of eariy pius iate restenosis was similar for patients in the infarction and the elective angioplasty groups (39 vs. 46%, respectively), white early restenosis is common in patients undergoing emergency angioplasty for acute myocardial infarction. Early angiograpbic restenosis or reoeclusion at the angioplasty site before hospital diiharge, oozurs in 631% of patients with initially successful angioplasty [I]. Early (about 1 month follow-up) restenosis after elective angioplasty was, however, low in a recent study using repeat angiography or staged coronary angioplasty 121. Our data are in good agreement with these observations. There is no clear explanation for the higher incidence of early restenosis after successful entergency angioplssty, though several factors may exist. Firstly, in emergency angioplasty of a total or subtotal infarct-related artery, information on the lesion (for example, degree and morphology of the underlying stenosis) is not adequate, therefore sutfkient balloon-size or Sation pressure
may be unsuitable. Secondly, the majority of infarct-related lesions are associated with a large thrombus that may be difficult to compress by balloon diiatation and may be adherent to the lesions. Thirdly, there may be redevelopment of thrombus at the site of a previously thrombosed atrial segment, as a result of persistent activation of platelets and residual fibrin deposits. Our data, in which lesion regression after angioplasty was found more frequently in patients undergoing emergency angiopfasty than in patients undergoing elective angioplasty, may reflect thrombus formation. The rate of long-term angiographic restenosis after successful emergency angioplasty with or without thrombolysis, has been reported in wera1 small series of patients and it ranges from 7-45% [1,3-S]. The majority of physicians generally did not perform routine long-term follow-up angiography in the absence of reCurrent symp tams. The late restenosis rate in the present study is 26%. which is a moderate level among published rates. Previous studies, examining angiographic follow-up after successful angioplasty on an elective basis, have found Lhat 17-40% of patients develop coronary restenosis [6-X]. These studies, however, failed to standardize the time of angiographic study. Nobuyoshi et al. [2] reported that the actuarial restenosis rate was 12.7% at 1 month and 43.0% at 3 months and that restenosis rarely occurred beyond 3 months. In OUTstudy, resteoosis was observed in 12% of 52 lesions at 1 month, and in 37% of 104 lesions at 3-6 months. These findings show a low late restenosis rate in patients treated with emergency an@oplasty for acu!e myocardial infarction. In conclusion, OUTresults suggest that in the early stage after angioplasty, restenosis or reocclusion in patients undergoing successful emergency angioplasty is relatively high, while being relatively lower in the late stage than in those treated with elective angioplasty. The rcawn for the high early restenosis rate in patients with acute myocardial infarction is related to some combination of intimal dissection, recurrent formation of thrombus and iotraplaque hemorrhage. Considering this higher restenosis rate at 1 month and
the
lower,
but
still more
than
20Y0, rate
at 3-6
months, a follow-up angiography should be performed both prior to discharge and at 3-6 months after the procedure, in patients with acute myocardial infarction.