Ashesh N. Buch

Cannabis-associated myocardial infarction in a young man with normal coronary arteries.

BACKGROUND The use of cannabis is not usually regarded as a risk factor for acute coronary syndrome. However, several cases of myocardial infarction (MI) associated with cannabis use have been reported in the scientific literature. The etiology of this phenomenon is not known. OBJECTIVES To present a case of cannabis-associated MI in which atherosclerotic coronary disease was excluded as a potential etiology by intravascular ultrasound examination, and briefly review the other possible mechanisms by which this effect may be mediated. CASE REPORT We present the case of a previously healthy 21-year-old man who regularly smoked cannabis and presented to the Emergency Department with ST-elevation myocardial infarction after participating in a sport. He was also a cigarette smoker, but had no other conventional cardiovascular risk factors. At coronary angiography, a large amount of thrombus was found in the left anterior descending coronary artery. He recovered with medical treatment, and subsequent intravascular ultrasound examination showed no evidence of atherosclerosis at the site of the thrombus. CONCLUSION Cannabis-associated MI is increasingly recognized. The etiology is unclear, but we believe this is the first report of the phenomenon where atherosclerotic plaque rupture has been excluded as the cause with a high degree of confidence.

Radiation dose during coronary angiogram: relation to body mass index.

OBJECTIVE Ionising radiation based diagnostic and therapeutic cardiology and radiology procedures are very common in present day medical practice and are one of the largest medical sources of radiation to humans. The risk to health from radiation has been extensively documented. Obesity is becoming epidemic not only in the western world, but also in developing countries. In the present study we investigated if a patients Body Mass Index (BMI) has an effect on the radiation dose received by the patient and operator during diagnostic coronary angiography (CAG). METHODS We analysed data of 3678 consecutive patients who underwent CAG from September 2007 to April 2010 in our cardiac catheter laboratory. Trans-radial access was used in 622 patients, whereas 3056 patients underwent CAG through trans-femoral route. We calculated the radiation dose in dose area product (DAP) units and correlated it with body mass index, screening time, procedure time, contrast volume, vascular access route and individual operator. RESULTS Among the explored parameters, body mass index had the most significant association with the radiation dose during the procedure. Despite having similar procedure times and contrast doses, patients with increased BMI received much higher radiation dose during CAG. We also found the left anterior oblique (LAO) caudal and LAO cranial views produced the biggest increase in radiation dose in patients with a high BMI. There was no inter-operator variability. CONCLUSION Obese patients require more than double the radiation dose in comparison to those with normal BMI. The operator should be aware of the increased dose of radiation required when performing CAG in patients with increased BMI, and especially in LAO cranial and caudal views.

Fractional Flow Reserve/Instantaneous Wave-Free Ratio Discordance in Angiographically Intermediate Coronary Stenoses: An Analysis Using Doppler-Derived Coronary Flow Measurements

Objectives The study sought to determine the coronary flow characteristics of angiographically intermediate stenoses classified as discordant by fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR). Background Discordance between FFR and iFR occurs in up to 20% of cases. No comparisons have been reported between the coronary flow characteristics of FFR/iFR discordant and angiographically unobstructed vessels. Methods Baseline and hyperemic coronary flow velocity and coronary flow reserve (CFR) were compared across 5 vessel groups: FFR+/iFR+ (108 vessels, n = 91), FFR–/iFR+ (28 vessels, n = 24), FFR+/iFR– (22 vessels, n = 22), FFR–/iFR– (208 vessels, n = 154), and an unobstructed vessel group (201 vessels, n = 153), in a post hoc analysis of the largest combined pressure and Doppler flow velocity registry (IDEAL [Iberian-Dutch-English] collaborators study). Results FFR disagreed with iFR in 14% (50 of 366). Baseline flow velocity was similar across all 5 vessel groups, including the unobstructed vessel group (p = 0.34 for variance). In FFR+/iFR– discordants, hyperemic flow velocity and CFR were similar to both FFR–/iFR– and unobstructed groups; 37.6 (interquartile range [IQR]: 26.1 to 50.4) cm/s vs. 40.0 [IQR: 29.7 to 52.3] cm/s and 42.2 [IQR: 33.8 to 53.2] cm/s and CFR 2.36 [IQR: 1.93 to 2.81] vs. 2.41 [IQR: 1.84 to 2.94] and 2.50 [IQR: 2.11 to 3.17], respectively (p > 0.05 for all). In FFR–/iFR+ discordants, hyperemic flow velocity, and CFR were similar to the FFR+/iFR+ group; 28.2 (IQR: 20.5 to 39.7) cm/s versus 23.5 (IQR: 16.4 to 34.9) cm/s and CFR 1.44 (IQR: 1.29 to 1.85) versus 1.39 (IQR: 1.06 to 1.88), respectively (p > 0.05 for all). Conclusions FFR/iFR disagreement was explained by differences in hyperemic coronary flow velocity. Furthermore, coronary stenoses classified as FFR+/iFR– demonstrated similar coronary flow characteristics to angiographically unobstructed vessels.

Post-traumatic internal mammary artery pseudoaneurysm: A rare complication of pericardiocentesis

Before the advent of ultrasound, percutaneous pericardiocentesis was associated with relatively high mortality and complication rates (6% and 20–50%, respectively) [1–3]. Ultrasound (US)-guided pericardiocentesis has dramatically decreased the incidence of complications by direct visualization of the heart and other adjacent vital structures. US helps localize the size and location of the pericardial effusion, measure the distance from the chest wall, localize adjacent, vital organs, and determine the optimal access site to the effusion. We report a case of posttraumatic internal mammary artery pseudoaneurysm, a rare complication of pericardiocentesis.

Improving quality and outcomes of coronary artery bypass grafting procedures

ABSTRACT The evolution in the approach, clinical care and outcomes of ischemic heart disease, has been dramatic over the past decade. Optimizing medical therapy initially and throughout the care delivery process has been transformative. The addition of new physiologic data to the traditional anatomic framework for diagnosis and therapy of more extensive stable ischemic heart disease (SIHD) enables quality and outcomes improvements in this patient population overall and in the patient subsets of acute coronary syndrome and SIHD. In patients undergoing coronary artery bypass grafting (CABG), these developments have changed the objective goal of surgical revascularization over this time interval. This review discusses the opportunities for quality and outcomes improvement in CABG, in the context of SIHD overall.

Stent position in ostial lesion: how can I be sure?

Received 28 October 2014 Revised 1 November 2014 Accepted 5 November 2014 Percutaneous coronary intervention of an ostial lesion is a challenging procedure, even for experienced operators, especially if the angle between the bifurcating vessels is less than 75°, or if the lesion is 0, 0, 1, as per the Medina classification [1]. Various techniques have been described to achieve stable stent position in such lesions [2]. The intervention strategy for an ostial lesion of the left anterior descending artery (LAD) has to be decided upfront, either to aim for precise ostial stent position or to bring the stent back across the left circumflex (LCx) ostium into the left main stem.

Letter by Shah and Buch regarding article, "prasugrel plus aspirin beyond 12 months is associated with improved outcomes after TAXUS Liberté paclitaxel-eluting coronary stent placement".

We have read the article by Garratt et al1 with interest. It appears that the patients in this study were of lower risk with low rates of major adverse cardiac and cerebrovascular events after the initial 12 months. Thirty months of dual-antiplatelet therapy (DAPT) demonstrated a reduction in major adverse cardiac and cerebrovascular events, mainly by reducing nonfatal myocardial infarction and stent thrombosis but with no mortality benefit. This was at the expense of excess bleeding. However, outcomes after percutaneous coronary intervention (PCI) are dependent on operator skills and experience, stent technology, …