Transcatheter aortic valve implantation (TAVI) is nowadays a generally accepted treatment option for inoperable or high-risk patients with severe symptomatic aortic valve stenosis (AS).1–3 However, despite the notable developments in the technique, certain complications, such as those related to vascular access, are still common. The incidence of major vascular complications, according to the Valve Academic Research Consortium (VARC) definition, ranges between 5.0% and 23.3%.4 They are associated with increased procedural costs, prolonged hospitalization and increased mortality.5–7 Transfemoral (TF) access is the preferred access route for TAVI8 and most patients are eligible for this approach.9 Several variables have been identified as potential predictors of TF access complications, the most consistent being femoral artery diameter, arterial calcification and center experience.5,10–12 However, a standardized methodology to assess the vascular access site, in particular regarding calcification, is lacking.

This study sought to assess the incidence and predictors of vascular access site complications in patients undergoing TF TAVI.

During the study period 170 patients underwent TAVI, of whom 140 were treated through the TF route. Baseline patient and procedural characteristics are summarized in Tables 1 and 2. Mean age was 78.3±9.1 years and 52.1% were female. In the early experience group, patients had a lower body mass index (26.5±5.0 vs. 28.3±5.1 kg/m2, p=0.041); other clinical characteristics were similar between the groups. A CoreValve was implanted in 67.1% of patients (third-generation CoreValve [n=91] and CoreValve Evolut R [n=3]) and an Edwards SAPIEN valve (Edwards SAPIEN XT [n=29] and Edwards SAPIEN 3 [n=17]) in the remainder. Almost all patients (98.6%) underwent an MDCT access route assessment. Right TF access was used in 80.0% of patients and an 18F sheath in 86.4%. Iliofemoral MLD was 7.28±1.39 mm and mean sheath outer diameter 6.87±0.43 mm, giving a SIFAR of 0.98±0.19. In 27 patients no calcium was identified in the iliofemoral access; mean iliofemoral CS was 256.6±582.9. Closure of the femoral artery access site was performed percutaneously using the Prostar XL device in 75.0% and Perclose ProGlide devices in 25.0%. In the late experience group, despite the trend to use smaller sheath sizes, there was a higher SIFAR (1.02±0.21 vs. 0.94±0.16, p=0.025). The use of Perclose ProGlide devices increased over time (45.7% vs. 4.3%, p<0.001).

According to the VARC-2 criteria, 51 patients (36.4%) presented vascular access site complications, which were major in 10 patients (7.1%) and minor in 41 (29.3%). The most common access site complications were local bleeding or hematoma (11.4%), pseudoaneurysm (7.9%) and closure device failure (5.0%) (Table 3). Almost half of patients who developed vascular access site complications were treated conservatively with external manual or mechanical compression, fluid therapy or blood transfusions. Most of the remaining cases were successfully treated with balloon or stent angioplasty. One patient underwent a retrograde recanalization technique to treat a left femoral artery occlusion and another underwent thromboembolectomy due to acute thromboembolic limb ischemia (Table 4). No patient required vascular surgery. The duration of hospital stay was 7.2±4.9 days and did not differ between patients who did and did not develop access site complications (p=0.574). The in-hospital mortality rate was 3.6%. Of these five deaths, one was directly related to vascular access site complication: hypovolemic shock resulting from retroperitoneal hemorrhage due to perforation of the iliac artery.

Univariate and multivariate logistic regression analysis for prediction of vascular access site complications are represented in Table 5. In a multivariate analysis that included factors with p<0.1 in univariate analysis (SIFAR, iliofemoral CS and center experience), SIFAR was the sole independent predictor of vascular access site complications (hazard ratio [HR] 14.5, 95% confidence interval [CI] 1.75–120.12, p=0.013). The SIFAR threshold with the highest sum of sensitivity (71.4%) and specificity (53.4%) for access site complications was 0.92 (area under the curve 0.66, 95% CI 0.56–0.75, p=0.002).

This study shows that vascular access site complications are still common among patients undergoing TF TAVI. We report an overall access site complication rate of 36.4%, higher than those described by other centers, which range between 5.0% and 23.3%.4 This is mainly due to a higher rate of minor complications (29.3%), in particular local bleeding or hematoma, which were treated conservatively in most cases. Previous investigations showed that minor vascular complications were not associated with increased hospital stay or with increased 30-day mortality.5

Several parameters have been indicated as potential predictors of access site complications. In our study, as well as clinical and procedural variables we assessed diameter and calcification of iliofemoral access by MDCT. SIFAR reflects both sheath size and iliofemoral MLD and was shown to be the only independent predictor of overall access site complications. We found that the best SIFAR threshold to predict access site complications was 0.92. This threshold is slightly more restrictive compared to other studies,5,17 probably because we considered prediction of both major and minor complications. In a prospective study of 130 TAVI patients, Hayashida et al. found that a SIFAR threshold of 1.05 (assessed by angiography or MDCT) predicted a higher rate of VARC major complications and 30-day mortality.5 MDCT is the preferred method to determine iliofemoral luminal diameter,18 however angiography has shown a good correlation with measurements obtained by MDCT.17 The predictive value of other variables, such as minimal luminal area or diameter derived from minimal luminal area, has never been assessed.

Some reports demonstrate that iliofemoral calcification is an important predictor of major vascular complications in patients undergoing TF TAVI.5,17,19 In these studies iliofemoral calcification was graded semi-quantitatively (from 0 – no calcification – to 3 – marked calcification) by MDCT or angiography. To our knowledge, this is the first study in which iliofemoral calcification was assessed quantitatively. We defined empirical thresholds to determine iliofemoral CS in contrast-enhanced MDCT images and found that the total amount of calcium in the iliofemoral segment was not a predictor of access site complications. Recently, Reinthaler et al. showed that iliofemoral calcification assessed semi-quantitatively by MDCT or angiography was not a predictor of vascular complication in a TF TAVI population, but the presence of circumferential calcification (>75%) assessed by MDCT was.17

In the late experience group there was an unexpected trend toward a higher access site complication rate compared to the early experience group. However, when adjusted for other variables in the multivariate analysis this trend was no longer present (p=0.429). This is mainly explained by the treatment of patients with progressively higher SIFAR by TF access (0.94±0.16 in early experience vs. 1.02±0.21 in late experience, p=0.025). In addition, during our TAVI program we gradually changed from Prostar to ProGlide closure devices, which could have nullified the benefits of the greater experience with the former. These differences between the first and second halves preclude an accurate assessment of the learning effect, however most other studies reported a significant reduction in the rate of vascular complications with increasing experience.5,11,12

Based on our findings, we expect a reduction in vascular access site complications with the introduction of progressively smaller delivery systems.

This is a retrospective single-center study with a mixed cohort of recipients of self-expandable and balloon expandable valves. The small sample size does not allow assessment of independent predictors of major access site complications only and their impact on morbidity and mortality.

Other factors that could lead to access site complications, such as the degree of vessel tortuosity and of circumferential calcification, were not analyzed in this study.

Vascular access site complications are frequent in patients undergoing TF TAVI. SIFAR was the only independent predictor of access site complications and therefore should be systematically assessed during pre-procedural imaging study.

The authors have no conflicts of interest to declare.