Physiologic Guidance of Infrainguinal Vascular Interventions Using the Pressure Wire.

OBJECTIVES: To assess the relationship between the resting (RG) and hyperemic (HG) translesional peripheral gradients, with the functional and anatomic parameters before and after an infrainguinal endovascular procedure. BACKGROUND: RGs and HGs are objective tools in defining the hemodynamic significance of an arterial stenosis. METHODS: In 25 subjects with infrainguinal arterial stenosis, RG and HG were measured via a pressure wire before and after angioplasty. Before and after the procedure, all subjects had an ankle-brachial index (ABI) and Duplex ultrasound evaluation, recording prelesion and in-lesion peak systolic velocity (PSV-L), and calculating a peak systolic velocity ratio (PSV-R). A Pearson R correlation coefficient was calculated. RESULTS: The mean age was 73 ± 12 years, 70% were men, median Rutherford class 3. At baseline and after angioplasty, mean ABI was 0.78 ± 0.2 and 0.99 ± 0.1, mean PSV-L was 459 ± 110 cm/s and 126 ± 35 cm/s, and mean PSV-R was 6.7 ± 4 and 1.2 ± 0.5, respectively. RG and HG significantly improved (P<.001) from baseline to after angioplasty (28.7 ± 20.5 mm Hg to 5 ± 13 mm Hg and 40.2 ± 21.4 mm Hg to 10 ± 13 mm Hg, respectively). RG before and after the procedure correlated well with ABI (r = -0.58; r = -0.41), PSV-L (r = 0.40; r = 0.52), and PSV-R (r = 0.46; r = 0.42). An improvement of 9 mm Hg in RG predicted a change of 0.1 in ABI. CONCLUSIONS: Improvement in RG during endovascular intervention in superficial femoral artery correlates well with the improvement in ABI, PSV-L, and PSV-R. A postprocedural decrease in RG of 9 mm HG predicts an improvement in ABI of 0.1.

Successful expansion of an underexpanded stent by rotational atherectomy.

The current routine use of intracoronary stents in percutaneous coronary intervention (PCI) has significantly reduced rates of restenosis, compared with balloon angioplasty alone. On the contrary, small post-stenting luminal dimensions due to undilatable, heavily calcified plaques have repeatedly been shown to significantly increase the rates of in-stent restenosis. Rotational atherectomy of lesions is an alternative method to facilitate PCI and prevent underexpansion of stents, when balloon angioplasty fails to successfully dilate a lesion. Stentablation, using rotational atherectomy to expand underexpanded stents deployed in heavily calcified plaques, has also been reported. We report a case via the transradial approach of rotational-atherectomy-facilitated PCI of in-stent restenosis of a severely underexpanded stent due to a heavily calcified plaque. We review the literature and suggest rotational atherectomy may have a role in treating a refractory, severely underexpanded stent caused by a heavily calcified plaque through various proposed mechanisms.

Transradial measurement of transvalvular pressure gradient in the setting of mechanical aortic and mitral valve prostheses using a coronary fractional flow reserve guidewire.

Accurate measurement of transvalvular pressure gradients is essential to comprehensively evaluate whether mechanical prosthetic valves are functioning normally. Direct measurements can be technically complicated, traditionally requiring direct, transapical puncture in the setting of both aortic and mitral mechanical valve prostheses. Very few case reports have proposed the use of guidewires indicated for coronary fractional flow reserve assessment to evaluate the transvalvular pressure gradients and hemodynamic status of patients with both aortic and mitral valve mechanical prostheses. We present one such case of a 59-year-old male with history of rheumatic heart disease and double mechanical valve replacements of the aortic and mitral valves presenting with contradictory clinical signs and noninvasive testing evidence of decompensated congestive heart failure and possible dysfunction of a mechanical, bi-leaflet aortic valve prosthesis. The use of a low-profile, intracoronary guidewire with a pressure transducer near the distal tip indicated for coronary fractional flow reserve determination proved very useful to answer this important question. Additionally, we report the first case of the use of this technology for this purpose via the radial artery access approach.

The impact of iso-osmolar contrast use in emergent percutaneous coronary intervention for ST-segment elevation myocardial infarction.

The incidence of contrast-induced nephropathy (CIN) in primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) was previously reported to be as high as 19%. Iso-osmolar contrast has frequently been used for populations at high risk for CIN, but a recent meta-analysis did not show a significant benefit of using iso-osmolar contrast in preventing CIN. The aim of our study is to evaluate the impact of iso-osmolar contrast use in patients undergoing emergent PCI. We performed a retrospective analysis of patients who underwent primary and rescue PCI for STEMI. The PCI strategy, including the contrast choice, was left at the discretion of the operator. CIN was defined as an increase in creatinine of more than 0.5 mg or 25% from the baseline within 72 hours. Among 212 patients, CIN was seen in 33 patients (16%). Patients who received iso-osmolar contrast were older, and included more patients at risk for CIN. The incidence of CIN was 14% in the low-osmolar contrast group and 17% in the iso-osmolar contrast group (P=.799). After logistic regression analysis, CIN was seen more frequently in patients who had lower ejection fraction, post-PCI TIMI flow <3, and lower hemoglobin. The use of iso-osmolar contrast was not associated with a lower incidence of CIN in patients undergoing emergent PCI for STEMI.

Transradial cardiac catheterization: a review of access site complications.

Transradial catheterization (TRC) has been associated with a lower incidence of major access site related complications as compared to the transfemoral approach. With the increased adoption of transradial access, it is essential to understand the potential major and minor complications of TRC. The most common complication is asymptomatic radial artery occlusion, which rarely leads to clinical events, owing to the dual collateral perfusion of the hand. Adequate anticoagulation, appropriate compression techniques, and smaller sheath size can minimize the risk of radial artery occlusion. Hand ischemia with necrosis has never been reported during TRC with thorough pre-examination of intact collateral circulation. Radial artery spasm is relatively common, and can result in access and procedural failure. It can be prevented by the use of vasodilator cocktails and hydrophilic sheaths. Radial artery perforation can lead to severe forearm hematoma and compartment syndrome if not managed promptly. Careful observation, prompt detection of the hematoma, and management with a pressure bandage dressing are critical to avoid serious complications. Pseudoaneurym and arteriovenous fistula are rare complications, which can likely be managed conservatively without surgical intervention. Nerve injury occurring during access has been reported. Close observation for improvement is necessary, although symptoms usually improve over time. In summary, to prevent access site complications, avoidance of multiple punctures, gentle catheter manipulation, use of guided compression, coupled with careful observation for adverse warning signs such as hematoma, loss of pulse, pain, are critical for safe and effective TRC.

Intra-aortic balloon pump use and outcomes with current therapies.

OBJECTIVES: Our purpose was to describe the contemporary utilization, clinical outcomes and complication rates of intra-aortic balloon pump (IABP) therapy in this current age. BACKGROUND: IABP use and outcomes, in the setting of modern antiplatelet therapy and primary percutaneous coronary intervention and the use of drug-eluting stents as we know them today, have not been clearly established. METHODS: We performed a retrospective cohort study by collecting detailed clinical and device data from all 150 consecutive patients who received IABP therapy in our institution between 2004 and 2009. RESULTS: Thrombocytopenia occurred in 50%, fever in 36%, bleeding in 27%, and vascular embolic events in 1%. Thrombocytopenia was the most common adverse event and was not significantly associated with the use of antiplatelet agents. The presence of diabetes mellitus, elevated white blood cells at presentation, and longer duration of IABP were significantly associated with the development of fever. Furthermore, those who developed fever had higher in-hospital mortality (31% versus 16%; p = 0.0487). CONCLUSIONS: In this contemporary cohort of IABP patients, complication rates of thrombocytopenia, fever and bleeding were relatively high but similar to prior studies, even in this current era of revascularization and antiplatelet medications.

Electrocardiographic predictors of culprit artery in acute inferior ST elevation myocardial infarction.

BACKGROUND: In acute inferior ST-segment elevation myocardial infarction (STEMI), multiple electrocardiographic algorithms have been proposed to predict the culprit artery. Our purpose is to review these and compare them to ST depression in lead aVR to predict culprit artery in inferior STEMI. METHODS: In 106 patients with acute inferior STEMI who underwent emergent coronary angiography, we correlated electrocardiographic and angiographic findings pertaining to the culprit artery. We then reviewed the algorithms proposed by Fiol et al and Tierala et al, and applied them and our own from Kanei et al using ST depression in aVR for predicting the left circumflex artery (LCx) as the culprit, to the population. Finally, we compared the sensitivities and specificities of the respective algorithms for predicting the culprit artery. RESULTS: The sensitivity and specificity of ST depression in lead aVR to predict LCx as the culprit were 53% and 86%, respectively, and 86% and 55%, respectively for predicting the right coronary artery (RCA) as the culprit. When their algorithms were applied to our population, the sensitivities and specificities of Fiol et al and Tierala et al were slightly higher. CONCLUSION: Compared to other proposed algorithms, ST depression in aVR is a simple method with satisfactory sensitivity and specificity to predict the culprit artery in inferior STEMI.

Randomized comparison of transradial coronary angiography via right or left radial artery approaches.

Previous studies have shown that the right radial approach encounters more tortuosity than the left radial approach during transradial coronary angiography. The objective of this study was to compare the procedural difficulty of the right and left radial approaches in the modern era with dedicated transradial catheters. One hundred ninety-three patients scheduled for transradial coronary angiography with normal Allen test results and without histories of coronary artery bypass grafting were randomized to the right or left radial approach. The choice of catheter was left to the discretion of the operator, with the preferred catheter being a dedicated transradial Optitorque catheter. The primary end point was procedural difficulty, defined as (1) hydrophilic or coronary wire use for tortuosity, (2) stiff wire use for the coronary engagement, (3) multiple catheters used, or (4) nonselective injection. The clinical characteristics were similar between the 2 groups. Procedural success was achieved in 98 of 101 (98%) in the right radial group and 91 of 92 (99%) in the left radial group. Procedural difficulty, fluoroscopy time, and contrast use were similar between the 2 groups. The use of a single catheter was more common in the right radial group (73% vs 18%, p <0.001). In conclusion, procedural success and difficulty were similar in the comparison groups. The right and left radial approaches are feasible and effective to perform coronary angiography and intervention.

Tips and tricks for stenting of bifurcation coronary lesions.

Although the provisional stenting technique to treat coronary bifurcation lesions is the preferred method, many bifurcation lesions still require a two-stent technique to optimize the result and clinical outcome. This manuscript summarizes the tips and tricks of bifurcation stenting with cases illustrations. As interventionists are encountering more complex and difficult cases, one may find the tips and tricks in this manuscript helpful in daily practice.

Coronary artery occlusion and myocardial infarction caused by vasospasm within a myocardial bridge.

Myocardial bridging is a common congenital coronary anomaly that is clinically silent in the majority of cases. Case reports suggest myocardial ischemia and infarction can be caused by myocardial bridging. The proposed mechanisms by which myocardial bridging causes myocardial ischemia include compromised coronary blood flow, endothelial dysfunction, thrombus formation and a strong association with coronary vasospasm. We reported a case of myocardial infarction caused by both myocardial bridging and coronary vasospasm. We reviewed the literature and suggest that coronary stenting may have a role in treating myocardial ischemia due to myocardial bridging and coronary spasm that is refractory to medical management.

ST-segment depression in aVR as a predictor of culprit artery and infarct size in acute inferior wall ST-segment elevation myocardial infarction.

BACKGROUND: ST-segment depression in lead aVR in acute inferior wall ST-segment elevation myocardial infarction (STEMI) has recently been suggested as a predictor of left circumflex (LCx) artery involvement. The purpose of this study is to evaluate the clinical significance of aVR depression during inferior wall STEMI. METHODS: This study included 106 consecutive patients who presented with inferior wall STEMI and underwent urgent coronary angiogram. Clinical and angiographic findings were compared between patients with and without aVR depression > or = 0.1 mV. RESULTS: The sensitivity and specificity of aVR depression as a predictor of LCx infarction were 53% and 86%, respectively. In patients with right coronary artery infarction, aVR depression was associated with increased cardiac enzymes and the involvement of a large posterolateral branch, which may explain the larger infarction. CONCLUSIONS: ST-segment depression in lead aVR in inferior wall STEMI predicts LCx infarction or larger RCA infarction involving a large posterolateral branch.