Canadian Cardiovascular Society 2022 Guidelines for Peripheral Arterial Disease.

Patients with widespread atherosclerosis such as peripheral artery disease (PAD) have a high risk of cardiovascular and limb symptoms and complications, which affects their quality of life and longevity. Over the past 2 decades there have been substantial advances in diagnostics, pharmacotherapy, and interventions including endovascular and open surgical to aid in the management of PAD patients. To summarize the evidence regarding approaches to diagnosis, risk stratification, medical and intervention treatments for patients with PAD, guided by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework, evidence was synthesized, and assessed for quality, and recommendations provided-categorized as weak or strong for each prespecified research question. Fifty-six recommendations were made, with 27% (15/56) graded as strong recommendations with high-quality evidence, 14% (8/56) were designated as strong recommendations with moderate-quality evidence, and 20% (11/56) were strong recommendations with low quality of evidence. Conversely 39% (22/56) were classified as weak recommendations. For PAD patients, strong recommendations on the basis of high-quality evidence, include smoking cessation interventions, structured exercise programs for claudication, lipid-modifying therapy, antithrombotic therapy with a single antiplatelet agent or dual pathway inhibition with low-dose rivaroxaban and aspirin; treatment of hypertension with an angiotensin converting enzyme or angiotensin receptor blocker; and for those with diabetes, a sodium-glucose cotransporter 2 inhibitor should be considered. Furthermore, autogenous grafts are more effective than prosthetic grafts for surgical bypasses for claudication or chronic limb-threatening ischemia involving the popliteal or distal arteries. Other recommendations indicated that new endovascular techniques and hybrid procedures be considered in patients with favourable anatomy and patient factors, and finally, the evidence for perioperative risk stratification for PAD patients who undergo surgery remains weak.

Clinical and hemodynamic factors in predicting response to fluid challenge during right heart catheterization.

Fluid challenge during right heart catheterization has been used for unmasking pulmonary hypertension (PH) related to left-sided heart disease. We evaluated the clinical and hemodynamic factors affecting the response to fluid challenge and investigated the role of fluid challenge in the classification and management of PH patients. We reviewed the charts of 67 patients who underwent fluid challenge with a baseline pulmonary arterial wedge pressure (PAWP) of ≤ 18 mmHg. A positive fluid challenge (PFC) was defined as an increase in PAWP to > 18 mmHg after 500 mL saline infusion. Clinical characteristics and echocardiographic and hemodynamic parameters were compared between PFC and negative fluid challenge (NFC). PFC was associated with female sex, increased BMI, and hypertension. A greater rise in PAWP was observed in PFC (6.8 ± 2.3 vs. 3.8 ± 2.7 mmHg, P = 0.001). A larger increase in PAWP correlated with a lower transpulmonary gradient (r = -0.42, P < 0.001), diastolic pulmonary gradient (r = -0.42, P < 0.001), and pulmonary vascular resistance (r = -0.38, P < 0.001). We found 100% of the patients with PFC were classified as WHO group 2 PH compared to 49% of the NFC patients ( P < 0.001). Fewer patients with PFC were started on advanced PH therapies and more were discharged from PH clinic. A PFC and the magnitude of PAWP increase after saline loading are associated with parameters related to left heart disease. In our population, fluid challenge appeared to influence the classification of PH and whether patients are started on therapy or discharged from clinic.

Comparison of thermodilution and indirect Fick cardiac outputs in pulmonary hypertension.

BACKGROUND: The accurate measurement of cardiac output (CO) is required in patients with pulmonary hypertension (PH).While both the thermodilution (TDCO) and indirect Fick (IFCO) methods are commonly used, there is little data comparing them in patients with PH. METHODS: We performed a retrospective analysis of patients evaluated at our center. All patients who had right heart catheterization (RHC) within 3 months of an echocardiogram, and CO assessment by both TDCO and IFCO methods were included. Bland-Altman analysis was used to assess agreement between the two methods. We further evaluated their agreement in each sex, and within tertiles of age, BMI and TR severity. We investigated the correlation between each method of CO and objective parameters of right ventricular function on echocardiography. RESULTS: In a cohort of 168 patients, the correlation between IFCO and TDCO was modest at (r = 0.61). On average, values for CO were lower with IFCO than with TDCO, by 0.62 L/min (95% CI -0.82, -0.40). This difference was greater for females: 0.86 L/min (95% CI -1.08, -0.63) and in the highest tertile of BMI: 0.97 L/min (95% CI -1.4, -0.55). Moderate and severe TR did not in general result in lower TDCO values. Echocardiographic parameters of right ventricular function were correlated more strongly with TDCO than with IFCO. CONCLUSION: In PH patients, IFCO was substantially lower than TDCO on average, suggesting that these two techniques cannot be used interchangeably. TDCO correlated more strongly with echocardiographic measures of RV function, suggesting that it may be preferred over IFCO.

Validity of algorithm for estimating left sided filling pressures on echocardiography in a population referred for pulmonary arterial hypertension.

The determination of LV filling pressure is integral to the diagnosis of pulmonary arterial hypertension (PAH). The American Society of Echocardiography (ASE) has devised algorithms for their estimation. We aimed to test these algorithms in a population referred for suspected PAH. In our retrospective study, we evaluated the accuracy of the ASE Algorithms compared to right heart catheterization done within three months, in patients seen during 2006-2014. All echocardiograms were classified as showing normal, elevated or indeterminate filling pressures. Those with indeterminate pressures were excluded. We evaluated the diagnostic properties of this algorithm to predict a pulmonary artery wedge pressure (PAWP) and left ventricular end diastolic pressure (LVEDP) >15 mmHg. A total of 94 patients were included. The ASE algorithms yielded indeterminate results in 50 (53.2%) patients. This occurred more commonly in older patients and patients with cardiovascular comorbidities. The algorithm had a high sensitivity for predicting an elevated PAWP at 89.5% (95% confidence interval [CI] = 66.9-98.7) and an elevated LVEDP at 100% (95% CI = 76.8-100). The algorithm had a negative predictive value of 81.8% and 100% for predicting an elevated PAWP (95% CI = 52.4-94.8) and LVEDP, respectively, but a poor positive predictive value. The ASE algorithm for predicting LV filling pressures often cannot be applied in populations with suspected PAH. When they are interpretable, they have a high negative predictive value for elevated PAWP and LVEDP. We recommend caution when using these algorithms in populations with suspected PAH.