Between July 2015 and September 2015, a total of 106 consecutive patients who underwent a transradial approach due to suspected stable coronary artery disease were enrolled in the study. Patients with previous transradial coronary revascularization, acute coronary syndrome, abnormal pulse oximetry plethysmography test, hemodynamic impairment, uncontrolled hypertension, vasculopathy, or inability to tolerate nitroglycerin or lidocaine due to allergy or medication interactions were excluded. In total, 16 patients were excluded, and 90 patients were included and randomized.

Hypertension was defined as documented systolic blood pressure of ≥140 mmHg and/or diastolic blood pressure of ≥90 mmHg in at least two measurements or active use of any antihypertensive agent. Diabetes was diagnosed as fasting plasma glucose over 126 mg/dl or 2-h glucose over 200 mg/dl in any measurement or active use of an antidiabetic agent. Smoking was defined as current smoking. Patients’ weight and height were recorded and body mass index (BMI) was calculated as weight in kg divided by the square of height in m. Body surface area (BSA) was calculated using the Mosteller formula.

Blood samples were obtained from the antecubital vein after a 12-hour fasting period. A Coulter LH series analyzer (Beckman Coulter Inc., Hialeah, FL) was used to obtain a complete blood count. Plasma levels of triglycerides, high-density lipoprotein, low-density lipoprotein, glucose, and creatinine were assessed using an automated chemistry analyzer (Abbott Aeroset, USA) using commercially available kits (Abbott, USA).

The study complied with the principles of the Declaration of Helsinki and was approved by the local ethics committee. All patients provided written informed consent before the procedure.

All patients underwent radial artery ultrasound before catheterization. The radial artery was measured using B-mode ultrasound (Mindray M7 system, Mindray Medical International Limited, Shenzhen, PRC), using a 7L4s linear probe (5-10 mHz) before the procedure. The radial artery was located, and radial diameters were measured 3 cm proximal to the styloid process at the R peak of the electrocardiogram. For each image, the mean of five measurements was obtained.

Patients undergoing transradial cardiac catheterization were randomized to a combination of subcutaneous nitroglycerin plus diltiazem or to manual heating (Balbay maneuver). The operators were blinded to the study. The operator's assistant used one of the two methods, and then cardiac catheterization was performed by the operator. The baseline patency of the palmar arch was assessed with a combination of pulse oximetry and plethysmography as described by Barbeau et al.22 in all patients. Patients with a type D response on the Barbeau test were excluded from the study. Routine prior sedation with agents such as midazolam or diazepam was not used in the study. In the first study arm, 200 mg nitroglycerin plus 2 mg diltiazem subcutaneously was used at the time of local anesthesia (1% lidocaine subcutaneously) regardless of the presence of a faint radial pulse. In the other study arm, manual heating (Balbay maneuver) was applied to all patients regardless of the presence of a faint radial pulse. The Balbay maneuver is defined as heating the radial artery site for three minutes with the palm (Figure 1) after administration of 1% lidocaine for local anesthesia subcutaneously. An arterial sheath is then inserted into the artery. In the study we used the Seldinger technique with a single anterior wall puncture. The artery was punctured with a sharp hollow needle, the syringe was detached and the guidewire advanced through the lumen of the needle, and the needle was withdrawn. A 10-cm 6F hydrophilic sheath (Radifocus Introducer II, Terumo, Leuven, Belgium) was then passed over the guidewire into the vessel.23,24 After sheath insertion, a radial cocktail containing 2 mg diltiazem, 200 mg nitroglycerin and heparin 5000 IU diluted in a 10-ml syringe was injected gradually through the sheath side arm into the radial artery. Coronary angiography was performed using 6F catheters (Boston Scientific). All coronary angiograms were performed by two interventional cardiologists experienced in radial access.

Figure 1.

Manual heating of the radial artery with the palm (Balbay maneuver).

(0.08MB).

The study endpoint was puncture score, defined as score 1: successful puncture at first attempt; score 2: second attempt; score 3: third attempt; score 4: fourth attempt or more; score 5: puncture failed.

SPSS 21.0 for Windows (IBM SPSS Inc., Chicago, IL, USA) was used for statistical analysis. Continuous variables were expressed as means ± standard deviation and categorical variables were expressed as numbers and percentages. The Kolmogorov-Smirnov test was used to test normality of distribution and the Student's t test and the Mann-Whitney U test were used to compare parametric and nonparametric continuous variables, respectively. Differences between treatment groups for categorical variables were analyzed using the chi-square test. A p value <0.05 was considered significant.

A total of 90 patients were enrolled in the study, 45 randomized to subcutaneous nitroglycerin plus diltiazem and 45 to manual heating (Balbay maneuver). The mean age of the participants was 60.2±10.8 years and 68.8% were male. Baseline characteristics and laboratory parameters were similar between groups with the exception of aspirin use (p>0.05). Patients’ weight, height, BMI, and BSA were similar between the groups (p>0.05) (Table 1). Complications were rare: one hematoma in the drug treatment group and one radial artery occlusion in the heating group. Baseline radial artery diameter was similar between the groups (2.41±0.46 vs. 2.29±0.48 mm; p=0.242). There was also no difference between the groups in blood pressure (p>0.05). Puncture score was lower in patients with manual heating than in those treated with subcutaneous nitroglycerin plus diltiazem (2 [1-3]) vs. 1 [1-2]; p=0.001) (Table 2). Successful puncture of the radial artery at the first attempt was significantly more common in the manual heating group (p=0.001) (Table 3).

The authors declare that the procedures followed were in accordance with the regulations of the relevant clinical research ethics committee and with those of the Code of Ethics of the World Medical Association (Declaration of Helsinki).

The authors declare that they have followed the protocols of their work center on the publication of patient data.

The authors have obtained the written informed consent of the patients or subjects mentioned in the article. The corresponding author is in possession of this document.