Percutaneous transluminal angioplasty hardly improves ambulation status in CLTI patients

Patients with chronic limb-threatening ischaemia (CLTI) who underwent percutaneous transluminal angioplasty (PTA) in Singapore have low 1-year mortality and 2-year lower extremity amputation (LEA) rates, reports a recent study. PTA, however, fails to significantly improve ambulation status.

In addition, end-stage renal failure (ESRF) and low albumin levels independently predict mortality, while ESRF/chronic kidney disease (CKD) and Wound Ischaemia and Foot Infection (WIFI) score independently predict loss of ambulation at 6 months and 1 year.

“These factors can potentially be utilized to risk stratify our CLTI patients to decide who might benefit more from a limb-salvage strategy, instead of subjecting all of these high-risk patients to a revascularization-first approach,” the researchers said. “This study also opens a new field for investigation into whether correction of anaemia and albumin preoperatively may improve postsurgical outcomes in CLTI patients among Asians.”

This study analysed CTLI patients who underwent PTA between January 2015 and March 2017 at the Vascular Unit at Singapore General Hospital. Thirty-day unplanned readmission, 2-year major LEA, mortality rates, and ambulation status at 1, 6, and 12 months were the primary endpoints.

A total of 221 procedures were carried out on 207 patients, majority (n=184; 88.9 percent) of whom were diabetics. Mortality rate at 1, 6, and 12 months was 7.7 percent, 16.4 percent, and 21.7 percent, respectively. LEA rate at 2 years was 30.0 percent. Only 96 (46.4 percent) and 93 (44.9 percent) patients were ambulant at 6 and 12 months, respectively. [Singapore Med J 2020;doi:10.11622/smedj.2020104]

On multivariate analysis, the following factors independently predicted 1-year ambulatory status: preoperative ambulatory status, haemoglobin, WIFI score, and ESRF. Furthermore, the independent predictors of mortality at 1, 6, and 12 months were as follows: preoperative albumin level, impaired functional status, employment status, and ESRF.

“Our finding that less than half of the patients could walk independently at 6 and 12 months after lower limb revascularisation is important in our local context, where much emphasis is placed on mobility,” the researchers said. “The loss of mobility is perceived as a major disability and represents lack of relevance to the workforce in our society.”

In other studies that involved non-Asian populations, successful angioplasty did not necessarily lead to improved functional outcomes. A study by Davies and El-Sayed found less than half of the patients (<40 percent) maintained ambulation after 1 year, while that of Duggan and colleagues showed no significant difference between patients who had undergone a successful limb salvage procedure and those who had not. [Am J Surg 1994;168:188-191; J Vasc Surg 2015;62:1555-1563]

Surprisingly, diabetes mellitus (DM) was not a predictor of any outcomes despite the contribution of DM to greater complexity of vascular disease. [Catheter Cardiovasc Interv 2018;92:117-123; Diabetes Care 2001;24:1433-1437]

“DM is characterized by hyperglycaemia, dyslipidaemia, and insulin resistance, which lead to derangements in vessel wall, fostering development and progression of peripheral arterial disease,” the researchers said. “A possible reason is that the glycated haemoglobin control of the patients in this study was relatively good (median 7.2 percent) at the time of PTA.” [Atherosclerosis 2008;197:237-241; JAMA 2002;287:2570-2581; Diabetes Care 1999;22:453-458]

The current study was limited by its retrospective design with the associated selection and information biases. In addition, information on the technical success and patency rates of the intervention were not obtained, according to the researchers.