Treatment of Peripheral Arterial Occlusive Disease around the Globe: Malta

Introduction: Malta is a small island in the middle of the Mediterranean with a population of 514,564 inhabitants and is served by one public tertiary hospital, Mater Dei Hospital. The Vascular unit was set up in 2007. The aim of this review is to analyse the work related to peripheral arterial occlusive disease (PAOD) in Malta with an in-depth focus on amputations and revascularisation procedures since the introduction of the Vascular unit. Method: Various sources of data have been interrogated to address this subject. Population and prevalence data on obesity and type II diabetes mellitus from 2003 to 2019 was obtained from the National Statistics Office, the World Health Organization, and the International Diabetes Federation, respectively. The Maltese Vascular Register (MaltaVasc), and in-hospital reports from 2003 to 2019 was used to obtain data on revascularisation procedures, major amputations and minor amputation rates in Malta. Results: Malta has one of the highest rates of obesity in Europe. In 2015, the prevalence rate was 30.6%. Similarly, data from the International Diabetes Federation Atlas showed that the prevalence rate of T2DM among adults was 14% in 2017. There was a mean of 33 open/hybrid procedures per 100,000 population (28–38, 95% confidence interval) between 2005 and 2009 and a mean of 57 endovascular procedures per 100,000 population (46–68, 95% confidence interval) during the same time-period. From 2009 to 2019, there was a mean of 16 major amputations and 78 minor amputations per 100,000 population. Conclusion: A significant reduction in major amputation rates with an increase in minor amputation rates and revascularisation rates has been noted since the establishment of the vascular unit in Malta. During this period, there has been an increase in prevalence in obesity and T2DM together with an aging population.

MTHFR 677C>T (rs1801133) variant is associated with homocysteinemia but not with clinical severity in patients with peripheral arterial occlusive disease

The aim of this study was to evaluate the association between the MTHFR 677C > T (rs1801133) genetic variant with susceptibility and severity of peripheral arterial occlusive disease (PAOD) and with serum levels of homocysteine (Hcy). This case-control study enrolled 157 patients with PAOD attended at University Hospital of Londrina, and unrelated 113 healthy individuals from Southern Brazil. The clinical severity of the PAOD patients was assessed by Fontaine classification and anatomoradiological categories by Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC). The MTHFR 677C > T was genotyped using real-time polymerase chain reaction. The PAOD patients showed higher Hcy than controls but the Hcy did not differ according to Fontaine and TASC categories. Patients carrying the TT genotype (recessive model) or CT + TT (dominant model) presented higher levels of Hcy than those carrying other genotypes. In conclusion, the T allele of MTHFR 677C > T variant was associated with hyperhomocysteinemia in PAOD patients, but not in controls. Moreover, this variant was not associated with the clinical stage and the anatomoradiological categories of PAOD. Our data suggested a possible interaction between MTHFR 677C > T variant and the presence of other genetic, epigenetic and environment factors associated with PAOD on modulation the metabolism of Hcy.

A Reperfusion BOLD-MRI Tissue Perfusion Protocol Reliably Differentiate Patients with Peripheral Arterial Occlusive Disease from Healthy Controls

There is no established technique that directly quantifies lower limb tissue perfusion. Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) is an MRI technique that can determine skeletal muscle perfusion. BOLD-MRI relies on magnetic differences of oxygenated and deoxygenated hemoglobin, and regional changes in oxy/deoxyhemoglobin ratio can be recorded by T2* weighted MRI sequences. We aimed to test whether BOLD-MRI can differentiate lower limb tissue perfusion in peripheral arterial occlusive disease (PAOD) patients and healthy controls. Twenty-two PAOD patients and ten healthy elderly volunteers underwent lower limb BOLD-MRI. Reactive hyperemia was provoked by transient cuff compression and images of the gastrocnemius and soleus muscles were continuously acquired at rest, during ischemia and reperfusion. Key BOLD parameters were baseline T2* absolute value and time to T2* peak value after cuff deflation (TTP). Correlations between imaging parameters and ankle-brachial index (ABI) was investigated. The mean TTP was considerably prolonged in PAOD patients compared to healthy controls (m. gastrocnemius: 111 ± 46 versus 48 ± 22 s, p = 0.000253; m. soleus: 100 ± 42 versus 41 ± 30 s, p = 0.000216). Both gastrocnemius and soleus TTP values correlated strongly with ABI (−0.82 and −0.78, p < 0.01). BOLD-MRI during reactive hyperemia differentiated most PAOD patients from healthy controls. TTP was the most decisive parameter and strongly correlated with the ABI.