Diabetes mellitus as a predictor for radial artery vasoreactivity in patients undergoing coronary artery bypass grafting

Hif-1α/Slit2 Mediates Vascular Smooth Muscle Cell Phenotypic Changes in Restenosis of Bypass Grafts

Vascular smooth muscle cells (VSMCs) are involved in restenosis of bypass grafts and cause artery graft occlusion. This study aimed to explore the role of Slit2 in phenotypic switching of VSMCs and its effect on restenosis of vascular conduits. An animal model of vascular graft restenosis (VGR) was produced in SD rats and assessed by echocardiography. The expression of Slit2 and Hif-1α was measured in vivo and in vitro. After Slit2 overexpression, the migration and proliferation of VSMCs were detected in vitro, and the restenosis rates and phenotype of VSMCs were tested in vivo. The arteries of the VGR model presented significant stenosis, and Slit2 was decreased in VSMCs of the VGR model. In vitro, Slit2 overexpression inhibited the migration and proliferation of VSMCs, but Slit2 knockdown promoted migration and proliferation. Hypoxia induced Hif-1α but reduced Slit2, and Hif-1α negatively regulated Slit2 expression. Moreover, Slit2 overexpression weakened the rate of VGR and maintained the patency of artery bypass grafts, which suppressed the phenotypic switching of VSMCs. Slit2 inhibited the synthetic phenotype transformation to inhibit the migration and proliferation of VSMCs and delayed the VGR via Hif-1α.

Study on Influencing Factors of Radial Artery Occlusion after Repeated Right Radial Artery Coronary Intervention

Objective

To investigate the risk factors of radial artery obstruction after repeated right radial coronary interventions.

Methods

497 patients who underwent repeated coronary intervention via the right radial artery in our hospital from January 2017 to January 2021 were selected and followed up for 28.07 ± 6.07 months. According to whether the right radial artery was obstructed or not, they were divided into radial artery occlusion group (n = 48) and nonradial artery occlusion group (n = 449).

Results

The proportion of patients with diabetes mellitus, elevated D-dimer, and elevated LDL cholesterol was higher in the radial artery occlusion group than in the nonradial artery occlusion group (p < 0.05). The radial artery occlusion group had more passage through the right radial artery often and had a longer cumulative sheath retention time than the radial artery occlusion group (p < 0.05). Cumulative sheath retention time (hours) had a high predictive value for radial artery occlusion. The optimal diagnostic limit for radial artery occlusion was 2.75 h, with a sensitivity of 77.1% and a specificity of 79.5% (p < 0.05).

Conclusion

Diabetes mellitus, elevated D-dimer, elevated LDL cholesterol, and long retention sheath time predispose to radial artery occlusion. Cumulative duration of sheath retention is a predictor of radial artery occlusion.

Assessment of radial artery atherosclerosis in acute coronary syndrome patients: an in vivo study using optical coherence tomography

Background

Radial artery (RA) atherosclerosis in acute coronary syndrome (ACS) patients has not been systematically observed in vivo. The study aims to characterize plaque morphology and intimal hyperplasia of the RA in patients with ACS, using optical coherence tomography (OCT).

Methods

In this retrospective study involving 239 ACS patients underwent RA OCT without guidewire shadow, 3 groups were divided according to the following criteria: radial artery plaque (RAP) group included patients with fibrous, lipid or calcified plaque; patients without RAP were further classified into radial intimal hyperplasia (RIH) group (intima media thickness ratio [IMR] ≥ 1) or normal group (IMR < 1). The presence and characteristics of RAP and its related risk factors were identified.

Results

The RAP, RIH and normal groups included 76 (31.8%), 69 (28.9%) and 94 (39.3%) patients, respectively. Patients in RAP group were the oldest, compared with those in the RIH and normal groups (p < 0.001), and more frequently had triple vessel disease (p = 0.004). The percentage of plaque rupture (72.4% vs. 56.4%, p = 0.018) and calcification (42.1% vs. 27.6%, p = 0.026) at culprit lesion were significantly higher in patients with RAP than those without RAP. A total of 148 RAP were revealed by OCT, including fibrous (72, 48.6%), lipid (50, 33.8%) and calcified plaques (26, 17.6%). The microvessels were also frequently observed in the RAP group than that in RIH and normal groups (59.2% vs. 8.7% vs. 9.6%, p < 0.001). Multivariate logistic regression analysis showed that age, diabetes, and smoking history (all p < 0.05) were independent risk factors for RAP.

Conclusions

In terms of insights gained from OCT, RA atherosclerosis is not uncommon in ACS patients by OCT, sharing several morphological characters with early coronary atherosclerosis. Aging, diabetes, and smoking are risk factors for RAP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02561-5.

Is the result of modified Allen’s test still accurate after endoscopic thoracic sympathectomy?

Background

The radial artery (RA) is increasingly being used for coronary artery bypass grafting (CABG). Endoscopic thoracic sympathectomy (ETS) has been shown to block innervation of sympathetic nerves of upper limbs, which reduces sweating of hands and dilates blood vessels. The modified Allen’s test (MAT) is one of the commonest methods of assessing collateral arm flow prior to RA harvest, though it has limitations. However, the reliability of MAT after ETS remains unclear. We therefore investigated the effects of ETS on the results of MAT.

Methods

A retrospective cohort study was conducted on 164 consecutive Chinese patients with palmar hyperhidrosis who underwent ETS between January 2016 and January 2019. The medical records were reviewed concerning the ultrasound examination and MAT results of their RAs and ulnar arteries (UAs) in both forearms before and after ETS.

Results

The performance of ETS significantly increased the diameter of the right RA from 2.731±0.122 to 3.102±0.114 mm in men and from 2.347±0.074 to 2.915±0.162 mm in women. Similar effects of ETS were observed in expanding the diameters of the left RA and the UA. Meanwhile, there was no significant effect of ETS on systolic blood pressure (BP) and heart rate (HR). Overall, retesting of patients following ETS with a preoperative positive MAT result revealed a transition to a negative result.

Conclusions

ETS was effective in dilating RA in both men and women, which could lead to a false negative preoperative MAT result. Patients should be questioned about their history of ETS if their RAs are to be harvested for CABG. More studies are warranted to evaluate the safety of RA as a coronary artery graft after ETS.

Friend or foe: food-dependent exercise-induced anaphylaxis associated with acute coronary syndrome aggravated by adrenaline and aspirin: a case report

Background

Although aspirin and adrenaline are the guideline-recommended treatments for acute coronary syndrome (ACS) and anaphylaxis, both regimens can contribute to clinical worsening in the setting of concurrent ACS and anaphylaxis which is called allergic angina or Kounis syndrome.

Case summary

A 62-year-old woman with food-dependent exercise-induced anaphylaxis developed ACS after intramuscular injection of adrenaline for the treatment of anaphylaxis, whereas administered aspirin for the treatment of ACS exacerbated anaphylaxis.

Discussion

Our case underlines the importance of tailored treatment based on the underlying pathophysiology of individual patients. Clopidogrel and glucagon might be a better alternative for the treatment of Kounis syndrome.

Impaired Vascular Redox Signaling in the Vascular Complications of Obesity and Diabetes Mellitus

Significance: Oxidative stress, a crucial regulator of vascular disease pathogenesis, may be involved in the vascular complications of obesity, systemic insulin resistance (IR), and diabetes mellitus (DM). Recent Advances: Excessive production of reactive oxygen species in the vascular wall has been linked with vascular disease pathogenesis. Recent evidence has revealed that vascular redox state is dysregulated in cases of obesity, systemic IR, and DM, potentially participating in the well-known vascular complications of these disease entities. Critical Issues: The detrimental effects of obesity and the metabolic syndrome on vascular biology have been extensively described at a clinical level. Further, vascular oxidative stress has often been associated with the presence of obesity and IR as well as with a variety of detrimental vascular phenotypes. However, the mechanisms of vascular redox state regulation under conditions of obesity and systemic IR, as well as their clinical relevance, are not adequately explored. In addition, the notion of vascular IR, and its relationship with systemic parameters of obesity and systemic IR, is not fully understood. In this review, we present all the important components of vascular redox state and the evidence linking oxidative stress with obesity and IR. Future Directions: Future studies are required to describe the cellular effects and the translational potential of vascular redox state in the context of vascular disease. In addition, further elucidation of the direct vascular effects of obesity and IR is required for better management of the vascular complications of DM.

Long term outcomes of radial artery grafting in patients undergoing coronary artery bypass surgery

Single arterial left internal thoracic artery (LITA) based coronary artery bypass surgery (LITA-SABG) has been the principal revascularization strategy for over 25 years across all patient demographics. In line with the current emphasis being placed on personalized medicine, which tailors individual, patient-specific therapy to optimize outcomes, coronary artery bypass grafting (CABG) techniques have also evolved to achieve enhanced results among specific groups of patients with coronary artery disease. Most notable has been the development of multi-arterial bypass grafting (MABG) techniques, using either the radial artery (RA) or the right internal thoracic artery (RITA) in conjunction with the LITA, as both techniques have been shown to enhance long term survival of CABG patients. This article reviews the latest data on the long-term outcomes of RA-MABG and considers its impact in various sub-cohorts of CABG that are increasingly being treated by cardiac surgeons. The primary aim of this review is to highlight the advantages of RA-MABG over LITA-SABG and thereby potentiate its adoption into clinical practice. Our secondary aim is to summarize the results of RA-MABG in specific CABG sub-cohorts, to more closely align CABG surgery with the emerging consensus that personalized medicine enhances healthcare value.

Comparison of endothelial function of coronary artery bypass grafts in diabetic and nondiabetic patients: Which graft offers the best?

OBJECTIVE

Diabetes associated endothelial dysfunction, which determines both long and short term graft patency, is not uniform in all coronary artery bypass surgery (CABG) grafts. Herein this study, we aimed to investigate the degree of endothelial dysfunction in diabetic radial artery (RA), internal mammarian artery (IMA) and saphenous vein (SV) grafts in vitro tissue bath system.

METHODS

This is a prospective experimental study. Fifteen diabetic and 15 non-diabetic patients were included to the study. A total number of 96 graft samples were collected; 16 graft samples for each graft type from both diabetic and non-diabetic patients. Arterial grafts were harvested with pedicles and SV grafts were harvested by 'no touch' technique. Vasodilatation response of vascular rings to carbachol, which induces nitric oxide (NO) mediated vasodilatation, was designated as the measure of endothelial function.

RESULTS

The IMA grafts had the most prominent NO mediated vasodilatation in both diabetic and non-diabetic patients, concluding a better preserved endothelial function than SV and RA. The 'no- touch' SV and RA grafts had similar vasodilatation responses in non-diabetic patients. In diabetic patients, on the other hand, RA grafts exhibited the least vasodilatation response (ie. worst endothelial function), even less vasodilatation than 'no touch' SV grafts (p<0.0001).

CONCLUSION

Deteriorated function of RA grafts in diabetic patients, even worse than SV grafts made evident by this study, encourages the use of 'no touch' technique as the method of SV harvesting and more meticulous imaging of RA before its use as a graft in diabetic patients.

Impact of Diabetes Mellitus on Radial and Ulnar Arterial Vasoreactivity after Radial Artery Cannulation: A Randomized Controlled trial

BACKGROUND

Endothelial dysfunction associated with diabetes mellitus (DM) may influence arterial vasoreactivity after arterial stimulus, such as cannulation, and cause changes in diameter and blood flow. Despite the frequent use of arterial cannulation during anesthesia and critical care, little information is available regarding vasoreactivity of the radial and ulnar arteries and its influence on underlying DM.

METHODS

Forty non-DM and 40 DM patients, who required arterial cannulation during general anesthesia, were enrolled. Using duplex Doppler ultrasonography, we measured the patients' arterial diameter, peak systolic velocity, end-diastolic velocity, resistance index, and mean volume flow of both arteries at five different time points.

RESULTS

After radial artery cannulation, ulnar arterial diameter and blood flow did not significantly increase in DM group, as they did in non-DM group. Ulnar arterial resistance index significantly increased in both groups, but the degree of decrease in DM group was significantly less than non-DM.

CONCLUSION

Ulnar artery's ability to increase blood flow for compensating the sudden reduction of radial arterial flow in DM patients was significantly less than that in non-DM patients under general anesthesia. Such attenuated vasoreactivity of ulnar artery to compensate the reduced radial arterial flow may have to be considered in radial arterial cannulation for DM patients.

Coronary artery disease and diabetes mellitus

Diabetes mellitus (DM) is a major risk factor for cardiovascular disease. Near-normal glycemic control does not reduce cardiovascular events. For many patients with 1- or 2-vessel coronary artery disease, there is little benefit from any revascularization procedure over optimal medical therapy. For multivessel coronary disease, randomized trials demonstrated the superiority of coronary artery bypass grafting over multivessel percutaneous coronary intervention in patients with treated DM. However, selection of the optimal myocardial revascularization strategy requires a multidisciplinary team approach ('heart team'). This review summarizes the current evidence regarding the effectiveness of various medical therapies and revascularization strategies in patients with DM.

Radial artery as graft for coronary artery bypass surgery: Advantages and disadvantages for its usage focused on structural and biological characteristics

Radial artery (RA) is the most popular arterial graft after the left internal thoracic artery in both low- and high-risk patients undergoing coronary artery bypass grafting. Various arterial grafts such as the right internal thoracic artery, the right gastroepiploic artery, and the inferior epigastric artery have also gained ground over the past 30 years because of the intimal hyperplasia and atherosclerosis of the saphenous vein leading to late graft occlusion. In this review article we would like to present the utility of the RA as a graft, focused mainly on its structural and biological characteristics.

Comparative study on the histomorphology and molecular biology of radial artery conduits in patients with diabetes mellitus who underwent coronary bypass surgery

We studied the impact of diabetes mellitus (DM) on the radial artery (RA) in 30 patients with DM and 30 non-diabetic patients undergoing coronary artery bypass grafting with autologous RA. RAs were recorded as normal if there was no cellular or stromal tissue between the endothelium and the internal elastic lamina. The RA was normal in 26.7% of diabetic and 76.7% of non-diabetic patients (p = 0.000298). Intimal thickness index and intima:media ratio were higher in the former than in the latter (p < 0.05; p < 0.05), with no significant difference in luminal narrowing (p > 0.05). Electron microscopy scores were lower in the non-diabetic group (p < 0.001); endothelial nitric oxide synthase (eNOS) protein expression and optical density were higher (p < 0.001). Von Willebrand factor and endothelin-1 messenger RNA (mRNA) levels were higher in the DM patients (p < 0.001). The quality of the RA in patients with DM was thus inferior to that in non-diabetic patients. Care should be taken when selecting RA as a conduit in patients with DM.

Improving long term outcome for diabetic patients undergoing surgical revascularization by use of the radial artery conduit: a propensity matched study

Background

Diabetes predicts worse outcomes after coronary artery bypass grafting (CABG) We hypothesized that a strategy using radial artery (RA) conduit(s) would improve outcomes and long term survival for diabetic patients undergoing CABG with Left Internal Thoracic Artery (LITA) and RA grafts, with or without additional saphenous vein (SV) when compared with outcomes for patients bypassed with LITA and SV but no RA.

Methods

A propensity matched study of long term survival in diabetic patients who had isolated first time CABG from January 1995 to June 2010 at an urban academic medical center in New York City. Our primary endpoint was all cause mortality determined from the Social Security Death Index in December 2010.

Results

We compared our 15 year outcomes in diabetic patients after isolated, primary CABG: 642 patients received LITA + RA +/− SV (RA group) vs. 1201 patients who had LITA + SV only (SV group). Propensity scoring for multiple preoperative and operative variables matched 409 patients from each group: 68% were male with an average age of 61 years and ejection fraction averaged 47%. Average grafts per patient was 3.7 for both groups with 2.3 arterial grafts per patient for the RA group. Operative (30 day) mortality was 0.1% RA vs. 1.9% SV, (p<0.0001) For propensity matched patients, mortality was 0.25 RA vs 0.5% SV. (p<0.001) The incidence of major complications was similar in both groups. Kaplan Meier actuarial survival at 1, 5, 10 and 12 years was 98%, 89%, 77 and 70% for RA vs. 96%, 87%, 64% and 59% for SV (p<0.006.) By Cox multivariate analysis significant predictors of mortality were: age, stroke, peripheral vascular disease, COPD, creatinine > 2.5mg/dl and low ejection fraction but only RA use predicted better survival [HR 0.683, CI 0.507- 0.920, p=0.0122].

Conclusion

For diabetic patients having CABG with LITA, use of radial artery conduit adds a substantial and sustained survival advantage compared to LITA and vein. Optimal revascularization for diabetics with multi vessel disease is redefined.

Mesenteric endothelial dysfunction in a cardiopulmonary bypass rat model: the effect of diabetes

BACKGROUND

Diabetes is a risk factor for perioperative complications after cardiac surgery. We studied its effects on mesenteric endothelial function in a cardiopulmonary bypass (CPB) model.

METHODS

Forty Wistar rats were divided into four groups: sham (D-CPB-), cardiopulmonary bypass (D-CPB+), diabetic (D+CPB-) and diabetic that have undergone CPB (D+CPB+). Two samples of mesenteric artery were used for nitric oxide synthase (NOS) Western blot analysis, and two others for assessing contractile response and endothelium relaxations. Nitrite products and tumour necrosis factor-alpha (TNF-α) were assessed as markers of inflammatory response.

RESULTS

We observed an enhanced contractile response to the α-adrenergic agonist associated with impairment of mesenteric vasorelaxation in D+CPB+ rats. Western immunoblot analysis of D+CPB+ highlighted an additive effect of hyper-expression of inducible NOS. A significantly increased inflammatory response was observed after CPB in diabetic animals.

CONCLUSIONS

This work confirms the potential deleterious impact of diabetes on the mesenteric endothelium during CPB in cardiac surgery.

Role of CABG in the management of obstructive coronary arterial disease in patients with diabetes mellitus

Multiple studies have shown that diabetes mellitus (DM) can affect the efficacy of revascularization therapies and subsequent clinical outcomes. Selection of the appropriate myocardial revascularization strategy is critically important in the setting of multivessel coronary disease. Optimal medical therapy is an appropriate first-line strategy in patients with DM and mild symptoms. When medical therapy does not adequately control symptoms, revascularization with either PCI or CABG may be used. In patients with treated DM, moderate to severe symptoms and complex multivessel coronary disease, coronary artery bypass graft surgery provides better survival, fewer recurrent infarctions and greater freedom from re-intervention. Decisions regarding revascularization in patients with DM must take into account multiple factors and as such require a multidisciplinary team approach ('heart team').

Radial artery graft flowmetry is better than saphenous vein on postero-lateral wall

BACKGROUND

Although general agreement exists on internal mammary graft as the first conduit, the second choice is still questioned. Despite radial artery (RA) grafting has been suggested, saphenous veins (SV) continue to be extensively used.

METHODS

A prospective series of isolated RA-CABG (150 patients) or SV-CABG (180 patients), performed either off-pump (OP-CABG) and on-pump (CPB-CABG), in diabetics and non-diabetics, in elderly and young patients, during the last 5-years at a single institution were evaluated. RA was harvested with harmonic scalpel, flowmetry was performed with a transit-time flowmeter (TTF). Graft flow reserve (GFR) was calculated with intra-aortic balloon-pump. Follow-up was collected by outpatient clinic database or by telephone interview with general practitioners.

RESULTS

The 2 groups showed comparable preoperative and intraoperative variables. Mortality, morbidity, myocardial infarction, troponin I leakage, and echocardiographic parameters were comparable (p=NS). RA-CABG demonstrated significantly higher TTF maximum, mean and minimum flow (p<.001) with lower Pulsatility Index (p<.001), either in the circumflex and the right coronaries. Compared to SVG-grafting, significantly higher GFR was found in RA-CABG on the circumflex (p=.001) and right (p=.028) coronaries. 38.1+/-0.9 SE months follow-up resulted in higher survival and freedom from cardiac events in RA-CABG. Better TTF and GFR were demonstrated in OP-CABG, CPB-CABG, diabetics, non-diabetics, either on the circumflex and right coronary systems (p<.05). Better mean flow was detected in RA-CABG on the circumflex in the elderly (p=.04) and the young (p=.05).

CONCLUSIONS

RA-CABG demonstrated better TTF and GFR results compared to SV-CABG. These data may contribute to explain the survival benefit of arterial revascularization already reported.

The cholinomimetic agent carbachol induces headache in healthy subjects

The parasympathetic nervous system is likely to be involved in migraine pathogenesis. We hypothesized that the cholinomimetic agonist carbachol would induce headache and vasodilation of cephalic and radial arteries. Carbachol (3 microg/kg) or placebo was randomly infused into 12 healthy subjects in a double-blind crossover study. Headache was scored on a verbal rating scale from 0-10. Velocity in the middle cerebral artery (V(MCA)) and diameter of the superficial temporal artery (STA) and radial artery (RA) were recorded. Nine participants developed headache after carbachol compared with three after placebo. The area under the curve for headache was increased after carbachol compared with placebo both during infusion (0-30 min) (P = 0.042) and in the postinfusion period (30-90 min) (P = 0.027). Carbachol infusion caused a drop in V(MCA) (P = 0.003) and an increase in STA diameter (P = 0.006), but no increase in the RA diameter (P = 0.200). In conclusion, the study demonstrated that carbachol caused headache and dilation of cephalic arteries in healthy subjects.

Relation of preoperative radial artery flow-mediated dilatation to nitric oxide bioavailability in radial artery grafts used in off-pump coronary artery bypass grafting

The radial artery is prone to vasospasm after coronary bypass surgery, and endothelial dysfunction is likely to be a key factor. We investigated whether endothelial dysfunction in radial artery conduits is present, and can be identified, preoperatively using a simple noninvasive ultrasound test of radial artery endothelial response, flow-mediated dilatation (FMD). The study population consisted of 126 patients scheduled for coronary artery bypass grafting. The afternoon before operation, patients had noninvasive ultrasound assessment of endothelial function in the left radial artery by FMD, which measures change in arterial size after an increase in flow-an endothelial-dependent response. Surplus graft segments were obtained at operation and nitric oxide bioavailability within the vessels determined from ex vivo responses to acetylcholine. Preoperative FMD in the radial artery was associated with vasorelaxations to acetylcholine in radial artery grafts (p<0.001 for both dose-response curves and maximum relaxations), although there was weak borderline association between FMD and vasorelaxations of saphenous vein grafts (p=0.07 for dose-response curves and p<0.05 for maximum relaxations). In multivariate analysis including cardiac risk factors, FMD was a predictor of vasorelaxations of radial artery grafts (beta=0.020, SE=0.009, p=0.030), independent of classic risk factors for atherosclerosis. In conclusion, there is significant interindividual variation in the endothelial function of vessels used for coronary artery bypass surgery, particularly the radial artery. These differences are present and can be identified preoperatively by FMD.

Harmonic scalpel versus electrocautery for harvest of radial artery conduits: reduced risk of spasm and intimal injury on optical coherence tomography

OBJECTIVE

Vasospasm is the primary obstacle to widespread adoption of the radial artery as a conduit in coronary artery bypass grafting. We used optical coherence tomography, a catheter-based intravascular imaging modality, to measure the degree of radial artery spasm induced by means of harvest with electrocautery or a harmonic scalpel in patients undergoing coronary artery bypass grafting.

METHODS

Radial arteries were harvested from 44 consecutive patients with a harmonic scalpel (n = 15) or electrocautery (n = 29). Vessels were imaged before harvesting and after removal from the arm, with saphenous vein tracts serving as internal controls. Optical coherence tomographic findings for the degree of harvesting-induced injury were validated against histologic measures.

RESULTS

Optical coherence tomographic measures of endovascular dimensions and injury correlated strongly with histologic findings. Mean luminal volume, a measure of vasospasm, decreased significantly less after harvesting with a harmonic scalpel (9% +/- 7%) than with electrocautery (35% +/- 6%, P = .015). Completely intact intima was present in 11 (73%) of 15 radial arteries harvested with a harmonic scalpel (73%) compared with 9 of 29 arteries harvested by means of electrocautery (31%, P = .011). Intraoperative flow measurements and patency rates at 5 days postoperatively were not significantly different among groups.

CONCLUSIONS

Optical coherence tomography provides a level of speed and accuracy for quantifying endothelial injury and vasospasm that has not been described for any other modality, suggesting potential as an intraoperative quality assurance tool. Our optical coherence tomographic findings suggest that the harmonic scalpel induces less spasm and intimal injury compared with electrocautery.

The impact of diabetic status on coronary artery bypass graft patency: insights from the radial artery patency study

BACKGROUND

Despite worse outcomes in diabetics after coronary artery bypass grafting surgery, studies have not examined graft patency in this high-risk group. This study examined the impact of diabetes on graft patency, 1-year postcoronary artery bypass grafting, using data from a multicenter randomized trial.

METHODS AND RESULTS

The Radial Artery Patency Study enrolled 561 patients undergoing coronary artery bypass grafting, comparing graft patency of the saphenous vein (SV) versus radial artery 1-year postcoronary artery bypass grafting. Angiographic follow-up was acquired for 440 patients (115 diabetics, 325 nondiabetics), each with a study radial artery and a control SV graft. Preoperative characteristics were similar. The proportion of small-sized target vessels was greater in diabetics (P=0.04). At 1 year, 33 of 230 study grafts (14.4%) were occluded in the diabetics versus 63 of 650 (9.7%) in the nondiabetics (P=0.052). Multivariable regression found diabetes to be a significant independent predictor of 1-year graft occlusion (relative risk, 1.45; 95% CI, 1.03 to 2.05; P=0.03) along with female gender, SV conduit, and small target-vessel size. A significantly higher proportion of SV grafts were occluded in the diabetics (19% versus 12%, P=0.04). Radial artery grafting was protective in the diabetic cohort (radial artery: 11 of 115 occluded [9.5%] versus SV: 22 of 115 occluded [19.1%], McNemar corrected P=0.05; relative risk, 0.42; 95% CI, 0.16 to 1.01) and nondiabetics (radial artery: 25 of 325 occluded [7.7%] versus SV: 38 of 325 occluded [11.7%], McNemar corrected P=0.11; relative risk, 0.63; 95% CI, 0.35 to 1.10).

CONCLUSIONS

Coronary artery bypass grafting occlusions were more common among diabetics versus nondiabetics at 1-year angiography, mainly because of more frequent SV graft failure in diabetics. Radial artery, compared with SV grafting, is protective in both diabetic and nondiabetic patients.