ABSTRACT: Heart catheterization is frequently applied in patients with coronary artery disease for diagnostic and therapeutic implications. Using the femoral approach, post-procedure bed rest of 4–6 hours is recommended to prevent groin complications. This extended strict bed rest is associated with patient discomfort and increased medical costs, and interferes with more efficient catheterization laboratory management of referred outpatients. Accordingly, we tested a simple clinical approach to identify low-risk patients who may benefit from ambulation within two hours after sheath removal. Ninety-eight outpatients were stratified to early (time = 1.5–2.0 hours; n = 74) or conventional ambulation (time = 4–5 hours; n = 24) based on difficulties in obtaining arterial access, presence of oozing or hematoma after completing manual compression. Ecchymosis was the most frequent complication, noted in one early ambulated and three conventionally ambulated patients at hospital discharge and in eleven early ambulated and six conventionally ambulated patients at one-week follow-up. No large hematomas, retroperitoneal bleeding or need for blood transfusion occurred in any patients. Using simple clinical parameters, most outpatients who undergo elective diagnostic catheterization may benefit from safe early ambulation.
Key words: early ambulation, heart catheterization
Diagnostic and therapeutic heart catheterizations are common procedures in patients with coronary artery disease (CAD). In the United States alone, over half a million of these procedures are performed each year. The femoral approach to heart catheterization is the most commonly used, and post-procedure bed rest of 4–6 hours is traditionally recommended to prevent bleeding complications. This extended strict bed rest is associated with patient discomfort, extended hospital stay, increased utilization of healthcare resources and difficulties in implementation of an “in-and-out” outpatient catheterization strategy. Although the radial approach is sometimes applied to overcome these difficulties,1 its utilization has not gained much popularity and early ambulation after the femoral approach plus hemostasis with a sealing device is a costly alternative and used mostly after interventions.2 Previous meta-analyses showed that ambulation after two hours compared with six hours carries a similar bleeding risk (6–8%).3–5 However, in these studies, patients were randomly allocated to the treatment group without risk stratification. We hypothesize that ambulation within two hours is safe in patients stratified as low risk for bleeding complications.

Methods
Patient selection. We prospectively assessed the safety of early ambulation, defined as out of bed < 2 hours post-procedure, in 98 consecutive patients who underwent diagnostic heart catheterization between August 1999 and March 2000 at Soroka Medical Center. Patients were included if the procedure was performed via the femoral artery using a 6 French sheath. Exclusion criteria included unstable angina, pretreatment with oral anticoagulants, platelets count less than 150,000/µl, partial thromboplastin time (PTT) > 45 seconds and systolic blood pressure over 200 mmHg at the time of sheath removal. Patients were allowed conventional ambulation at operator discretion if: 1) difficulties were encountered in obtaining arterial access; 2) hematoma was present at the time of sheath removal; or 3) oozing was present after ten minutes of manual pressure. Early ambulation was performed in 74 patients and conventional ambulation was implemented in 24 patients. The main reasons for deferring patients from early ambulation were oozing upon completion of ten minutes of manual compression (n = 19), difficulties obtaining arterial access (n = 4) and hematoma at the time of sheath removal (n = 1).

Assessment of bleeding complications. Bleeding complications, defined as: 1) inguinal hematoma (small, < 5 cm; large, >= 5 cm); 2) inguinal ecchymosis; 3) retroperitoneal hematoma; or 4) need for blood transfusion, were assessed at the time of initial ambulation, prior to the patient’s hospital discharge and at 1-week follow-up. Pre-discharge assessment was performed 30 and 90 minutes after ambulation in the conventional and early ambulation groups, respectively. The extended time from ambulation to discharge in the early ambulation group was calculated to allow in-hospital assessment of bleeding complications at 3.5–4.0 hours after sheath removal.

Statistical analysis. Continuous variables were analyzed using student’s t-test and are presented as means ± standard deviation. Nominal variables were analyzed with Chi-square test or Fisher’s exact test and are expressed as percentages. p-values less than 0.05 were considered statistically significant.

Results
Patients. Baseline demographics and clinical data of the patients are summarized in Table 1. No significant differences were observed between early and conventional ambulation groups.

Ambulation time and bleeding complications. Times to ambulation and discharge were shorter in the early compared to conventional ambulation groups (103 ± 20 minutes versus 289 ± 7 minutes; p < 0.001 and 200 ± 47 minutes versus 316 ± 66 minutes; p = 0.001, respectively).

Early ambulation was associated with a very low incidence of in-hospital bleeding complications (Table 2). In both groups, bleeding complication rates did not increase at discharge compared to ambulation time. At one week, however, increased rates of minor bleeding complications were noted in both groups. No large hematomas, retroperitoneal bleeding or need for blood transfusion were observed.

Discussion
The current study suggests that early ambulation following diagnostic heart catheterization, in low-risk patients stratified by simple clinical parameters, is a safe strategy associated with very low bleeding complication rates. Several studies have demonstrated the safety of early ambulation after diagnostic cardiac catheterization.3,6–8 Mah et al. found similar complication rates after catheterization with 7 French sheaths among patients who were ambulated < 3 hours compared to more than three hours after sheath removal.8 Koch et al. demonstrated the safety of early ambulation (4 hours) in patients who underwent percutaneous transluminal coronary angioplasty with 6 French sheaths and low-dose heparin (5,000 Units).6 In a meta-analysis of early ambulation trials after diagnostic catheterization, Logemann et al. showed that six-hour bed rest after catheterization did not reduce local (groin) bleeding events compared to two-hour bed rest.3 In this analysis, bleeding complications, defined as hematoma < 5 cm with or without any bleeding, were observed in 6% and 8.4% of the early and late ambulation groups, respectively. In the current study, early ambulation was associated with no hematoma, and only one patient was diagnosed with ecchymoses. The main difference between the current and previous studies is the methodology of patient selection. Using simple clinical assessment, we were able to identify patients who were at low risk for groin bleeding. Moreover, despite the relatively short groin compression time (~ 10 minutes), no major bleeding complications were noted up to one-week follow-up.

In the current series, early bleeding complications in patients who had oozing after short groin compression or in whom arterial access was difficult to obtain were mainly ecchymosis, whereas hematoma was noted only in one patient. The rate of groin hematoma at one week in this group was 8%, which is in accord with previous studies.3

The risk of hematoma after invasive procedure depends on several factors, including low platelet count, puncture technique, efficacy of manual compression and patient compliance. Multiple punctures, puncture of the posterior arterial wall, puncture either too high or too low, and inadequate manual compression increase the risk of bleeding. Most of these factors can be assessed early, allowing the operator to promptly assess the bleeding risk. Using this approach, approximately 75% of outpatients who undergo 6 French diagnostic heart catheterization may benefit from early ambulation. The most frequent reason for deferring patients from early ambulation was oozing after completing ten minutes of compression; it is conceivable that slightly longer compression (i.e., 15–20 minutes) may allow better hemostasis. The current study, however, was not designed to assess the efficacy of different compression times.

Early ambulation can be readily achieved when the radial approach is used. This approach also allows early discharge and is associated with rare vascular complications. However, due to technical complexity, a long learning curve and a limited ability to use the larger sheaths needed for different devices, this approach has not been universally adopted. Therefore, the current study results may be applicable to the many centers where the radial approach is infrequently used.

Study limitations. This was a small, non-randomized study and its result may not be applied to a wider range of outpatients, including those with unstable angina or patients with slightly lower platelet counts. Other factors that may also affect bleeding rates, such as patient weight and body surface area, were not studied. In addition, only clinical parameters were used during follow-up, and the possibility of unrecognized complications, such as retroperitoneal bleeding, cannot be excluded. Similarly, the presence of pseudoaneurysms after the procedure was not routinely investigated using ultrasound. However, the absence of large hematomas or bleeding requiring blood transfusion indicates a very low probability that these complications did occur.

Conclusion. The current study suggests that early ambulation is feasible and safe in outpatients selected by simple bedside clinical assessment.