Impact of Elevated Perioperative Fasting Blood Glucose on Carotid Artery Stenting Outcomes Mark G. Davies, and Wael E. Saad, Houston, Texas
Background: Carotid artery stenting (CAS) for high-risk individuals is accepted practice. An impaired fasting hyperglycemia (IFG) is often associated with poor procedural outcomes after other percutaneous procedures. The clinical outcomes of CAS for patients with elevated fasting blood sugar (FBS) are not well defined. Methods: A database of patients undergoing CAS was sampled from 2000 to 2009. An IFG was defined as plasma glucose >110 mg/dL. Life table analyses were performed to assess time-dependent outcome differences between those patients with and without IFG. The outcomes of freedom from restenosis, occlusion, death, recurrent symptoms, and neurologic event were calculated. Cox proportional hazard analysis or Fisher’s exact test was performed to identify factors associated with outcomes. Results: During the study period 322 patients underwent 345 CAS procedures. The mean follow-up was 4.6 years. A total of 196 patients (61%) were male. The indications for CAS were neurologic symptoms in high-risk patients in 23% and asymptomatic high-risk in the remainder. Fifty-nine percent had an IFG but only 30% had a history of diabetes mellitus (DM). Patients with an IFG were more likely to suffer a major adverse event (MAE; death, myocardial infarction, stroke; 12% vs. 26%, 110 vs. >110, respectively, at 5 years, P ¼ 0.021 by chi-squared analysis) in the 90-day perioperative period. By life table analysis, there were no differences between normal and IFG patients with regards to freedom from occlusion or target vessel revascularization. The long-term MAE rate was significantly worse in patients with an IFG, driven by decreased survival and stroke rates. Patients carrying the diagnosis of DM had equivalent outcomes to non-DM patients (67 ± 5% vs. 62 ± 7%, 110 vs. >110, respectively, at 5 years, P ¼ 0.84). The presence of metabolic syndrome and/or the combination of diabetes and metabolic syndrome in the IFG group were drivers of increasing poor MAE rates. Conclusions: Patients with IFG undergoing CAS are at a greater risk for periprocedural morbidity and worse MAE in both the short and long term. The diagnosis of DM does not have a similar impact on outcomes. A current IFG, as opposed to a history of DM, should be considered an important risk factor when determining the suitability for CAS.
The purpose of all carotid interventions is to prevent stroke. Acute hyperglycemia predicts increased risk
of in-hospital mortality after ischemic stroke in nondiabetic patients and increased risk of poor functional recovery in nondiabetic stroke survivors.1,2 Elevated glucose levels during an acute ischemic
Presented at the Annual Meeting of the Eastern Vascular Society (September 2010; New York City, NY).
Center, Houston Methodist Hospital, 6550 Fannin, Smith Tower, Suite 1401, Houston, TX 77030, USA; E-mail: [email protected]
Vascular and Endovascular Surgery, Department of Cardiovascular Surgery, Houston Methodist DeBakey Heart & Vascular Center, Houston Methodist Hospital, Houston, TX.
Ann Vasc Surg 2014; 28: 1885–1891 http://dx.doi.org/10.1016/j.avsg.2014.07.001 Ó 2014 Elsevier Inc. All rights reserved. Manuscript received: April 2, 2014; manuscript accepted: July 1, 2014; published online: July 7, 2014.
INTRODUCTION
Correspondence to: Mark G. Davies, MD, PhD, MBA, Department of Cardiovascular Surgery, Houston Methodist DeBakey Heart & Vascular
1885
1886 Davies and Saad
stroke predisposes to parenchymal hematoma, which in turn determines a nonfavorable outcome at 3 months.3 The increases in glucose levels have been shown to lower the neuronal ischemic threshold4,5 and potentiate infarct volume after focal ischemia.6 Hyperglycemia at the time of carotid endarterectomy (CEA) has been associated with an increased risk of perioperative stroke or transient ischemic attack (TIA), myocardial infarction (MI), and death.7 This effect is independent of previous cardiac disease, diabetes, or other comorbidities.7 It remains unknown whether hyperglycemia during carotid artery stenting (CAS) predisposes to perioperative stroke and operative-related morbidity and mortality. The aim of this study is to examine the clinical impact of impaired fasting hyperglycemia (IFG) on the outcomes of CAS and test the hypothesis that the presence of hyperglycemia is associated with increased perioperative events.
METHODS Study Design A retrospectively collected database of patients undergoing CAS from 2000 to 2009 was created. Only patients undergoing primary carotid stenting were included. All reinterventions were excluded. An IFG was defined as a fasting plasma glucose 110 mg/dL within 24 hr before the procedure. Serum glucose was analyzed using a standard clinical chemistry analyzer. For each patient, demographics, symptoms, existing comorbid conditions, and risk factors for atherosclerosis were identified. Periprocedural parameters were obtained from the record. Follow-up was by clinical assessment and carotid duplex ultrasound scans performed at 1, 6, and 12 months after the intervention and every 6 months thereafter. The primary outcome of the study was major adverse event (MAE; death, MI, stroke). Additional outcomes of freedom from restenosis, occlusion, recurrent symptoms, and neurologic event were also calculated. Data utilization fell under the category of secondary use of preexisting data as defined by the institutional review board and the Health Insurance Portability and Accountability Act. Study Setting Academic Medical Center with 600 beds in a catchment area of 3 million people. It is a tertiary and quaternary referral facility. Study Population A total of 322 patients who underwent 345 CAS procedures were identified with an IFG within 24 hr
Annals of Vascular Surgery
before the procedure. The mean follow-up was 4.6 years. One hundred ninety-six patients (61%) were male. The indications for CAS were neurologic symptoms in high-risk patients in 23% and asymptomatic anatomic high risk in the remainder. Methods Patients underwent carotid stenting where carotid stenosis 80% was detected on duplex imaging and was confirmed on computed tomography angiography, magnetic resonance angiography, or diagnostic angiography. The patient was given clopidogrel (75 mg/day) and aspirin (81 mg/day) beginning 3 days before the intervention. Routine pre- and post-procedural neurology consultations were not requested unless the patient was symptomatic or part of a clinical/commercial study. After the stenting procedure, clopidogrel and aspirin were continued for life. All patients undergoing carotid stenting received a sufficient intravenous heparin or angiomax dose to achieve systemic anticoagulation during the carotid intervention (activated clotting time >250 sec). All carotid stenting procedures were performed in fixed imaging procedure rooms under conscious sedation. The RX Acculink Carotid Stent System (Abbott Vascular, Abbott Laboratories, Abbott Park, IL) was used in all cases. Patients were routinely kept in the hospital overnight and discharged home on the following day. Follow-up visits with carotid duplex ultrasound scans were performed as previously indicated. Patients who required interventions for clinically significant restenosis after CAS were evaluated with duplex ultrasound scans at 6-month intervals. All duplex ultrasound scans were performed at approved vascular laboratories accredited by the Intersociety Commission on Accreditation of Vascular Laboratories using the Methodist criteria. Restenosis was defined as the development of >50% stenosis (peak systolic velocity 225 cm/sec and internal carotid artery:common carotid artery 2.5 for 50% stenosis).8 Clinically significant stenosis was defined as luminal reduction of 80% or higher. The presence of a high-grade stenosis was verified by biplanar carotid angiography. Carotid angioplasty and possible stenting were subsequently performed by following the standard protocol upon confirmation of the restenotic lesions. Definitions Coronary artery disease was defined as a history of angina pectoris, MI, congestive heart disease, or prior coronary artery revascularizations. Cerebrovascular disease included a history of stroke, TIA, or carotid
Vol. 28, No. 8, November 2014
artery revascularization. Hypertension was defined as a systolic blood pressure >150 mm Hg or diastolic blood pressure >90 mm Hg on 3 occasions during a 6-month period. Hyperlipidemia was defined as fasting cholesterol >200 mg/dL, low-density lipoprotein >130 mg/dL, or triglycerides >200 mg/dL or active therapy for hyperlipidemia. Diabetes was defined as an Hemaglobin A1c (HbA1c) >7% or active therapy for diabetes. A death within 30 days of the procedure was considered procedure-related. A major complication was defined as any event, regardless of how minimal, not routinely observed after endoluminal therapy that required treatment with a therapeutic intervention or rehospitalization within 30 days of the procedure. MAE rate was defined using SAPPHIRE criteria.9 Unlike SAPPHIRE, patients did not have a troponin series performed or formal neurologic consultations. Primary patency was defined as a patent carotid segment without recurrent stenosis or the need for further intervention. Assistedprimary patency was defined as a patent carotid segment, which underwent further intervention within the inflow, treated vessel segment, or outflow of the treated vessel segment to improve patency. Secondary patency was defined as an occluded carotid vessel or a carotid with hemodynamic failure resulting in a surgical bypass. Loss of patency was defined according to accepted Society for Vascular Surgery (SVS) reporting standards.
Fasting blood sugar and carotid stent outcomes 1887
Table I. Patient characteristics, presenting symptoms, and comorbidities FBS Characteristic
110
>110
Patients 132 190 Male (%) 64 59 Average age (mean ± SD, 71 ± 10 71 ± 10 years) Symptoms (%) Asymptomatic 48 49 Transient ischemic attack 44 41 Stroke 8 10 Comorbidities (%) Current smoking 21 9 Coronary artery disease 37 51 Congestive heart failure 20 27 Cardiac arrhythmia 15 12 Hypertension 85 92 Diabetes mellitus 1 49 HbA1C (mean ± SD) 5.7 ± 1.2 7.6 ± 1.4 Hyperlipidemia 74 76 Metabolic syndrome 20 63 Chronic renal 15 21 insufficiency Previous cerebrovascular 13 16 events Degree of contralateral disease (%) Normal to 80 years of age were similar between the groups. There were significantly more patients with coronary artery
Immediate Outcomes Technical success was equivalent between the groups (Table II). While 30-day mortality was also similar, the 30-day cumulative morbidity was increased in those with IFG (Table II). Examination of individual systemic regional and access site complications did not identify any one particular area where significant differences in morbidity occurred (Table II). There was a significant difference in 30day cumulative morbidity if the patient with IFG had either a diagnosis of DM or metabolic syndrome (Table III). Patients with IFG were more likely to
1888 Davies and Saad
Annals of Vascular Surgery
Table II. Interventions and periprocedural complications
Table IV. Incidence of MAE in relation to the presence of diabetes mellitus and metabolic syndrome
FBS 110
Outcome or complication
Perioperative outcomes (%) Technical failure Mortality Morbidity Systemic (%) Cardiac Pulmonary Renal Regional (%) Stroke Transient ischemic attack Bradycardia Hypotension Local (%) Vasospasm Dissection Hematoma Arteriovenous fistula Pseudoaneurysm formation
>110
1 0 22
3 1 35
0.26 0.53 0.02
1 1 0
3 2 1
0.26 0.65 0.53
1 4 8 5
8 5 13 10
1.00 1.00 0.19 0.20
4 1 4 0 3
7 2 2 0 1
0.46 0.65 0.31 d 0.37
Table III. Incidence of periprocedural complication in relation to the presence of diabetes mellitus and metabolic syndrome FBS Condition (%)
110
No diabetes mellitus and no metabolic syndrome Diabetes mellitus only Metabolic syndrome only Diabetes mellitus and metabolic syndrome
FBS
P value
>110
P value
10
0
0.001
3 3 3
1 8 18
suffer a MAE (death, MI, stroke; 26% vs. 12%, P < 0.001 by chi-squared analysis) in the 90-day perioperative period; patients carrying the diagnosis of DM had equivalent immediate outcomes to nonDM patients. Patients presenting with either an acute TIA or stroke also had equivalent outcomes in both groups. There was a significant difference in MAE rates if the patient with IFG had either a diagnosis of DM or metabolic syndrome (Table IV). There was also a significant difference in patients with IFG and a presentation with acute neurologic symptoms (Table V). Long-Term Outcomes There were no significant differences between normal FBS and IFG patients with regards to primary
Condition (%)
110
>110
P value
No diabetes mellitus and no metabolic syndrome Diabetes mellitus only Metabolic syndrome only Diabetes mellitus and metabolic syndrome
5
4
0.0003
0 2 0
3 6 5
Table V. Incidence of MAE in relation to presenting neurologic symptoms (asymptomatic or symptomatic) and the presence of diabetes mellitus and/or metabolic syndrome FBS Condition (%)
Asymptomatic No diabetes mellitus and no metabolic syndrome Diabetes mellitus only Metabolic syndrome only Diabetes mellitus and metabolic syndrome Symptomatic No diabetes mellitus and no metabolic syndrome Diabetes mellitus only Metabolic syndrome only Diabetes mellitus and metabolic syndrome
110
>110
P value
3
3
0.06
0 4 0
2 7 6
7
6
0 0 0
6 4 5
0.001
patency (96 ± 5% vs. 95 ± 3%, 110 vs. >110, respectively, at 5 years), assisted primary patency (98 ± 5% vs. 98 ± 3%, 110 vs. >110, respectively, at 5 years), and secondary patency (98 ± 4% vs. 98 ± 5%, 110 vs. >110, respectively, at 5 years). There was a significant difference in freedom from restenosis (>50% stenosis; 98 ± 3% vs. 50 ± 8%, 110 vs. >110, respectively, at 5 years, P ¼ 0.021). The reintervention rates were the same in both groups. There was a significant difference in MAE between the groups with IFG patients having worse outcomes (Fig. 1A). This was driven by significant decreases in patient survival and lower freedom from stroke (Fig. 1B, C). Freedom from MI was equivalent (Fig. 1D). The presence of diabetes did not influence the MAE rate (67 ± 5% vs. 62 ± 7%, 110 vs. >110, respectively, at 5 years, P ¼ 0.84), although the presence of metabolic syndrome and the combined presence of diabetes and metabolic
Vol. 28, No. 8, November 2014
Fasting blood sugar and carotid stent outcomes 1889
Fig. 1. Life table analysis of patients in the 110 and >110 mg/dL groups. Data are the mean ± SEM, and the number of patients at risk is shown in the table. No error bars are shown if the SEM is >10% and the data
set terminates if the number at risk is 110 mg/dL on patients presenting with a stroke, which can be explained by a waiting period for stabilization before carotid intervention. Limitations This is a retrospective study and thus suffers from all aspects of a retrospective review. CAS procedures for patients with excessive high FBSs (>400 mg/dL) would have been canceled on the day of surgery and thus are not included in this review. Many of the carotid stents placed in this study were part of clinical trials and thus had particular inclusion and exclusion criteria that could have biased the outcomes. When comparing various studies in the literature, the level of FBS varies from 110 to 170 mg/dL. We chose our level because it matches the definition from the World Health Organization which uses fasting plasma glucose 6.1 mmol/L (110 mg/dL) and
Background: Carotid artery stenting (CAS) for high-risk individuals is accepted practice. An impaired fasting hyperglycemia (IFG) is often associated with poor procedural outcomes after other percutaneous procedures. The clinical outcomes of CAS for patients with elevated fasting blood sugar (FBS) are not well defined. Methods: A database of patients undergoing CAS was sampled from 2000 to 2009. An IFG was defined as plasma glucose >110 mg/dL. Life table analyses were performed to assess time-dependent outcome differences between those patients with and without IFG. The outcomes of freedom from restenosis, occlusion, death, recurrent symptoms, and neurologic event were calculated. Cox proportional hazard analysis or Fisher’s exact test was performed to identify factors associated with outcomes. Results: During the study period 322 patients underwent 345 CAS procedures. The mean follow-up was 4.6 years. A total of 196 patients (61%) were male. The indications for CAS were neurologic symptoms in high-risk patients in 23% and asymptomatic high-risk in the remainder. Fifty-nine percent had an IFG but only 30% had a history of diabetes mellitus (DM). Patients with an IFG were more likely to suffer a major adverse event (MAE; death, myocardial infarction, stroke; 12% vs. 26%, 110 vs. >110, respectively, at 5 years, P ¼ 0.021 by chi-squared analysis) in the 90-day perioperative period. By life table analysis, there were no differences between normal and IFG patients with regards to freedom from occlusion or target vessel revascularization. The long-term MAE rate was significantly worse in patients with an IFG, driven by decreased survival and stroke rates. Patients carrying the diagnosis of DM had equivalent outcomes to non-DM patients (67 ± 5% vs. 62 ± 7%, 110 vs. >110, respectively, at 5 years, P ¼ 0.84). The presence of metabolic syndrome and/or the combination of diabetes and metabolic syndrome in the IFG group were drivers of increasing poor MAE rates. Conclusions: Patients with IFG undergoing CAS are at a greater risk for periprocedural morbidity and worse MAE in both the short and long term. The diagnosis of DM does not have a similar impact on outcomes. A current IFG, as opposed to a history of DM, should be considered an important risk factor when determining the suitability for CAS.
The purpose of all carotid interventions is to prevent stroke. Acute hyperglycemia predicts increased risk
of in-hospital mortality after ischemic stroke in nondiabetic patients and increased risk of poor functional recovery in nondiabetic stroke survivors.1,2 Elevated glucose levels during an acute ischemic
Presented at the Annual Meeting of the Eastern Vascular Society (September 2010; New York City, NY).
Center, Houston Methodist Hospital, 6550 Fannin, Smith Tower, Suite 1401, Houston, TX 77030, USA; E-mail: [email protected]
Vascular and Endovascular Surgery, Department of Cardiovascular Surgery, Houston Methodist DeBakey Heart & Vascular Center, Houston Methodist Hospital, Houston, TX.
Ann Vasc Surg 2014; 28: 1885–1891 http://dx.doi.org/10.1016/j.avsg.2014.07.001 Ó 2014 Elsevier Inc. All rights reserved. Manuscript received: April 2, 2014; manuscript accepted: July 1, 2014; published online: July 7, 2014.
INTRODUCTION
Correspondence to: Mark G. Davies, MD, PhD, MBA, Department of Cardiovascular Surgery, Houston Methodist DeBakey Heart & Vascular
1885
1886 Davies and Saad
stroke predisposes to parenchymal hematoma, which in turn determines a nonfavorable outcome at 3 months.3 The increases in glucose levels have been shown to lower the neuronal ischemic threshold4,5 and potentiate infarct volume after focal ischemia.6 Hyperglycemia at the time of carotid endarterectomy (CEA) has been associated with an increased risk of perioperative stroke or transient ischemic attack (TIA), myocardial infarction (MI), and death.7 This effect is independent of previous cardiac disease, diabetes, or other comorbidities.7 It remains unknown whether hyperglycemia during carotid artery stenting (CAS) predisposes to perioperative stroke and operative-related morbidity and mortality. The aim of this study is to examine the clinical impact of impaired fasting hyperglycemia (IFG) on the outcomes of CAS and test the hypothesis that the presence of hyperglycemia is associated with increased perioperative events.
METHODS Study Design A retrospectively collected database of patients undergoing CAS from 2000 to 2009 was created. Only patients undergoing primary carotid stenting were included. All reinterventions were excluded. An IFG was defined as a fasting plasma glucose 110 mg/dL within 24 hr before the procedure. Serum glucose was analyzed using a standard clinical chemistry analyzer. For each patient, demographics, symptoms, existing comorbid conditions, and risk factors for atherosclerosis were identified. Periprocedural parameters were obtained from the record. Follow-up was by clinical assessment and carotid duplex ultrasound scans performed at 1, 6, and 12 months after the intervention and every 6 months thereafter. The primary outcome of the study was major adverse event (MAE; death, MI, stroke). Additional outcomes of freedom from restenosis, occlusion, recurrent symptoms, and neurologic event were also calculated. Data utilization fell under the category of secondary use of preexisting data as defined by the institutional review board and the Health Insurance Portability and Accountability Act. Study Setting Academic Medical Center with 600 beds in a catchment area of 3 million people. It is a tertiary and quaternary referral facility. Study Population A total of 322 patients who underwent 345 CAS procedures were identified with an IFG within 24 hr
Annals of Vascular Surgery
before the procedure. The mean follow-up was 4.6 years. One hundred ninety-six patients (61%) were male. The indications for CAS were neurologic symptoms in high-risk patients in 23% and asymptomatic anatomic high risk in the remainder. Methods Patients underwent carotid stenting where carotid stenosis 80% was detected on duplex imaging and was confirmed on computed tomography angiography, magnetic resonance angiography, or diagnostic angiography. The patient was given clopidogrel (75 mg/day) and aspirin (81 mg/day) beginning 3 days before the intervention. Routine pre- and post-procedural neurology consultations were not requested unless the patient was symptomatic or part of a clinical/commercial study. After the stenting procedure, clopidogrel and aspirin were continued for life. All patients undergoing carotid stenting received a sufficient intravenous heparin or angiomax dose to achieve systemic anticoagulation during the carotid intervention (activated clotting time >250 sec). All carotid stenting procedures were performed in fixed imaging procedure rooms under conscious sedation. The RX Acculink Carotid Stent System (Abbott Vascular, Abbott Laboratories, Abbott Park, IL) was used in all cases. Patients were routinely kept in the hospital overnight and discharged home on the following day. Follow-up visits with carotid duplex ultrasound scans were performed as previously indicated. Patients who required interventions for clinically significant restenosis after CAS were evaluated with duplex ultrasound scans at 6-month intervals. All duplex ultrasound scans were performed at approved vascular laboratories accredited by the Intersociety Commission on Accreditation of Vascular Laboratories using the Methodist criteria. Restenosis was defined as the development of >50% stenosis (peak systolic velocity 225 cm/sec and internal carotid artery:common carotid artery 2.5 for 50% stenosis).8 Clinically significant stenosis was defined as luminal reduction of 80% or higher. The presence of a high-grade stenosis was verified by biplanar carotid angiography. Carotid angioplasty and possible stenting were subsequently performed by following the standard protocol upon confirmation of the restenotic lesions. Definitions Coronary artery disease was defined as a history of angina pectoris, MI, congestive heart disease, or prior coronary artery revascularizations. Cerebrovascular disease included a history of stroke, TIA, or carotid
Vol. 28, No. 8, November 2014
artery revascularization. Hypertension was defined as a systolic blood pressure >150 mm Hg or diastolic blood pressure >90 mm Hg on 3 occasions during a 6-month period. Hyperlipidemia was defined as fasting cholesterol >200 mg/dL, low-density lipoprotein >130 mg/dL, or triglycerides >200 mg/dL or active therapy for hyperlipidemia. Diabetes was defined as an Hemaglobin A1c (HbA1c) >7% or active therapy for diabetes. A death within 30 days of the procedure was considered procedure-related. A major complication was defined as any event, regardless of how minimal, not routinely observed after endoluminal therapy that required treatment with a therapeutic intervention or rehospitalization within 30 days of the procedure. MAE rate was defined using SAPPHIRE criteria.9 Unlike SAPPHIRE, patients did not have a troponin series performed or formal neurologic consultations. Primary patency was defined as a patent carotid segment without recurrent stenosis or the need for further intervention. Assistedprimary patency was defined as a patent carotid segment, which underwent further intervention within the inflow, treated vessel segment, or outflow of the treated vessel segment to improve patency. Secondary patency was defined as an occluded carotid vessel or a carotid with hemodynamic failure resulting in a surgical bypass. Loss of patency was defined according to accepted Society for Vascular Surgery (SVS) reporting standards.
Fasting blood sugar and carotid stent outcomes 1887
Table I. Patient characteristics, presenting symptoms, and comorbidities FBS Characteristic
110
>110
Patients 132 190 Male (%) 64 59 Average age (mean ± SD, 71 ± 10 71 ± 10 years) Symptoms (%) Asymptomatic 48 49 Transient ischemic attack 44 41 Stroke 8 10 Comorbidities (%) Current smoking 21 9 Coronary artery disease 37 51 Congestive heart failure 20 27 Cardiac arrhythmia 15 12 Hypertension 85 92 Diabetes mellitus 1 49 HbA1C (mean ± SD) 5.7 ± 1.2 7.6 ± 1.4 Hyperlipidemia 74 76 Metabolic syndrome 20 63 Chronic renal 15 21 insufficiency Previous cerebrovascular 13 16 events Degree of contralateral disease (%) Normal to 80 years of age were similar between the groups. There were significantly more patients with coronary artery
Immediate Outcomes Technical success was equivalent between the groups (Table II). While 30-day mortality was also similar, the 30-day cumulative morbidity was increased in those with IFG (Table II). Examination of individual systemic regional and access site complications did not identify any one particular area where significant differences in morbidity occurred (Table II). There was a significant difference in 30day cumulative morbidity if the patient with IFG had either a diagnosis of DM or metabolic syndrome (Table III). Patients with IFG were more likely to
1888 Davies and Saad
Annals of Vascular Surgery
Table II. Interventions and periprocedural complications
Table IV. Incidence of MAE in relation to the presence of diabetes mellitus and metabolic syndrome
FBS 110
Outcome or complication
Perioperative outcomes (%) Technical failure Mortality Morbidity Systemic (%) Cardiac Pulmonary Renal Regional (%) Stroke Transient ischemic attack Bradycardia Hypotension Local (%) Vasospasm Dissection Hematoma Arteriovenous fistula Pseudoaneurysm formation
>110
1 0 22
3 1 35
0.26 0.53 0.02
1 1 0
3 2 1
0.26 0.65 0.53
1 4 8 5
8 5 13 10
1.00 1.00 0.19 0.20
4 1 4 0 3
7 2 2 0 1
0.46 0.65 0.31 d 0.37
Table III. Incidence of periprocedural complication in relation to the presence of diabetes mellitus and metabolic syndrome FBS Condition (%)
110
No diabetes mellitus and no metabolic syndrome Diabetes mellitus only Metabolic syndrome only Diabetes mellitus and metabolic syndrome
FBS
P value
>110
P value
10
0
0.001
3 3 3
1 8 18
suffer a MAE (death, MI, stroke; 26% vs. 12%, P < 0.001 by chi-squared analysis) in the 90-day perioperative period; patients carrying the diagnosis of DM had equivalent immediate outcomes to nonDM patients. Patients presenting with either an acute TIA or stroke also had equivalent outcomes in both groups. There was a significant difference in MAE rates if the patient with IFG had either a diagnosis of DM or metabolic syndrome (Table IV). There was also a significant difference in patients with IFG and a presentation with acute neurologic symptoms (Table V). Long-Term Outcomes There were no significant differences between normal FBS and IFG patients with regards to primary
Condition (%)
110
>110
P value
No diabetes mellitus and no metabolic syndrome Diabetes mellitus only Metabolic syndrome only Diabetes mellitus and metabolic syndrome
5
4
0.0003
0 2 0
3 6 5
Table V. Incidence of MAE in relation to presenting neurologic symptoms (asymptomatic or symptomatic) and the presence of diabetes mellitus and/or metabolic syndrome FBS Condition (%)
Asymptomatic No diabetes mellitus and no metabolic syndrome Diabetes mellitus only Metabolic syndrome only Diabetes mellitus and metabolic syndrome Symptomatic No diabetes mellitus and no metabolic syndrome Diabetes mellitus only Metabolic syndrome only Diabetes mellitus and metabolic syndrome
110
>110
P value
3
3
0.06
0 4 0
2 7 6
7
6
0 0 0
6 4 5
0.001
patency (96 ± 5% vs. 95 ± 3%, 110 vs. >110, respectively, at 5 years), assisted primary patency (98 ± 5% vs. 98 ± 3%, 110 vs. >110, respectively, at 5 years), and secondary patency (98 ± 4% vs. 98 ± 5%, 110 vs. >110, respectively, at 5 years). There was a significant difference in freedom from restenosis (>50% stenosis; 98 ± 3% vs. 50 ± 8%, 110 vs. >110, respectively, at 5 years, P ¼ 0.021). The reintervention rates were the same in both groups. There was a significant difference in MAE between the groups with IFG patients having worse outcomes (Fig. 1A). This was driven by significant decreases in patient survival and lower freedom from stroke (Fig. 1B, C). Freedom from MI was equivalent (Fig. 1D). The presence of diabetes did not influence the MAE rate (67 ± 5% vs. 62 ± 7%, 110 vs. >110, respectively, at 5 years, P ¼ 0.84), although the presence of metabolic syndrome and the combined presence of diabetes and metabolic
Vol. 28, No. 8, November 2014
Fasting blood sugar and carotid stent outcomes 1889
Fig. 1. Life table analysis of patients in the 110 and >110 mg/dL groups. Data are the mean ± SEM, and the number of patients at risk is shown in the table. No error bars are shown if the SEM is >10% and the data
set terminates if the number at risk is 110 mg/dL on patients presenting with a stroke, which can be explained by a waiting period for stabilization before carotid intervention. Limitations This is a retrospective study and thus suffers from all aspects of a retrospective review. CAS procedures for patients with excessive high FBSs (>400 mg/dL) would have been canceled on the day of surgery and thus are not included in this review. Many of the carotid stents placed in this study were part of clinical trials and thus had particular inclusion and exclusion criteria that could have biased the outcomes. When comparing various studies in the literature, the level of FBS varies from 110 to 170 mg/dL. We chose our level because it matches the definition from the World Health Organization which uses fasting plasma glucose 6.1 mmol/L (110 mg/dL) and
