Mandeep Singh Randhawa

Diagnostic Utility of Cardiac Biomarkers in Discriminating Takotsubo Cardiomyopathy From Acute Myocardial Infarction

BACKGROUND Takotsubo cardiomyopathy (TC) mimics acute myocardial infarction (AMI). We postulated that ventricular dysfunction in TC in the absence of significant myocardial necrosis would produce higher B-type natriuretic peptide (BNP)/troponin T (TnT) and BNP/creatine kinase MB fraction (CKMB) ratios than in AMI. METHODS AND RESULTS We studied 58 consecutive TC (age 65.8 ± 82.9) and 97 AMI patients (age 59.8 ± 83.4). The ratios of BNP/TnT and BNP/CKMB were calculated with the use of first simultaneously drawn laboratory values. Receiver operating characteristic curves were used to distinguish TC from AMI with 95% specificity based on cardiac biomarker ratios. Median BNP/TnT and BNP/CKMB ratios were, respectively, 1,292 [interquartile range 443.4-2,657.9] and 28.44 [13.7-94.8] in the TC group and 226.9 [69.91-426.32] and 3.63 [1.07-10.02] in the AMI group (P < .001). TC can be distinguished from AMI with 95% specificity with the use of BNP/TnT ratio ≥ 1,272 (sensitivity 52%) and BNP/CKMB ratio ≥ 29.9 (sensitivity 50%). CONCLUSIONS The value of BNP is significantly higher in TC than in AMI. Early BNP/TnT and BNP/CKMB ratios help to differentiate TC from AMI with greater accuracy than BNP alone.

Transfer Metrics in Patients With Suspected Acute Aortic Syndrome

National guidelines by the American College of Cardiology, American Heart Association, and European Society of Cardiology have established benchmarks for patient transfer times (door-in-door-out time and door-to-balloon time) that serve as clinical performance measures for ST-segment–elevation myocardial infarction (STEMI) networks. Campaigns, such as D2B Alliance and Mission Lifeline, were also launched in an effort to reduce system delays in transfer and improve outcomes for subjects presenting with STEMI.1 This scrutiny on pre- and interhospital care has led to marked reductions in door-to-balloon times across the United States.2 Unlike STEMI, acute aortic syndrome (AAS) defined as acute aortic dissection, intramural hematoma, or penetrating aortic ulcer is a less frequent clinical event that lacks an effective diagnostic biomarker and requires definitive imaging for confirmation. The time-sensitive nature of AAS, complexity of surgery, and endovascular intervention and the relative paucity of institutions that deliver 24/7 state-of-the-art care strongly advocates for regional systems of care across the United States. Successful transfer of patients with AAS has previously been described through such efficient regional care models.3,4 Our aim was to evaluate safety and timeliness of transfer provided by our regional aortic network. The transfer metrics served by this analysis will help us improve as a network and more importantly serve as a benchmark to be replicated and improved on by others. Our AAS network shares a common hotline with our STEMI and stroke networks. On activation, a transfer team is dispatched immediately to the referring center. The transfer system is operated by critical care trained nurse practitioners and paramedics, who are equipped in handling all cardiovascular emergencies under direct consultation with cardiac intensive care unit (CCU) physicians. The transfer team’s goal is to expedite safe …

Utility of Glycated Hemoglobin for Assessment of Glucose Metabolism in Patients With ST-Segment Elevation Myocardial Infarction

Glycated hemoglobin (HbA1c) is an approved and widely used laboratory investigation for diagnosis of diabetes that is not affected by acute changes in blood glucose. Our aim was to analyze the extent to which routine HbA1c measurements diagnose unknown diabetes mellitus (DM) in patients presenting with ST-segment elevation myocardial infarction (STEMI). We also compared outcomes in patients with newly diagnosed DM, previously established DM and those without DM. Consecutive patients undergoing PCI for STEMI from January 2005 to December 2012 were included and routinely performed admission HbA1c was used to identify patients with previously undiagnosed DM (HbA1c ≥6.5 and no history of DM or DM therapy) and pre-DM (HbA1c 5.7% to 6.4%). Overall 1,686 consecutive patients underwent primary percutaneous coronary intervention for STEMI during the study period and follow-up data were available for 1,566 patients (90%). A quarter of the patients (24%, n = 405) had history of DM, 7% (n = 118) had previously undiagnosed DM, and 38.7% (n = 652) had pre-DM. Mortality was comparable in patients with known DM and newly diagnosed DM both in-hospital (11.1% vs 11.9%, p = 0.87) and at 3-year follow-up (27.3% and 24%). Patients with DM, including those who were newly diagnosed, had higher mortality at 3 years (26.5%) compared to those with pre-DM (12.1%) or no dysglycemia (11.2%, p <0.01). In conclusion, a substantial number of patients with STEMI have previously undiagnosed DM (7%). These patients have similar in-hospital and long-term mortality as those with known DM, and outcomes are inferior to patients without dysglycemia.

Perioperative outcomes of patients with hypertrophic cardiomyopathy undergoing non-cardiac surgery

Objective Due to their unique pathophysiological profile, patients with hypertrophic cardiomyopathy (HCM) undergoing non-cardiac surgery require additional attention to perioperative management. We sought to compare perioperative outcomes of patients with HCM undergoing non-cardiac surgery with a matched group patients without HCM. Methods This observational cohort study conducted at a tertiary care centre included patients with HCM (n=92, age 67 years, 54% men) undergoing intermediate-risk and high-risk non-cardiac surgeries between 1/2007 and 12/2013 (excluding <18 years, prior septal myectomy/alcohol ablation, low-risk surgery) who were 1:2 matched (based on age, gender, type and time of non-cardiac surgery) with patients without HCM (n=184, median age 65 years, 53% men). A composite endpoint (30-day postoperative death, myocardial infarction, stroke, in-hospital decompensated congestive heart failure (CHF) and rehospitalisation within 30 days) and postoperative atrial fibrillation (AF) were recorded. Results There was a significantly lower incidence of intraoperative hypotension/tachycardia in patients with HCM versus those without HCM (p<0.001). At 30 days postoperatively, 42 (15%) patients had composite events. Rates of 30-day death, MI or stroke were very low in patients with HCM (5%). However, a significantly higher proportion of patients with HCM met the composite endpoint versus patients without HCM (20 (22%) vs 22 (12%), p=0.03), driven by decompensated CHF. On logistic regression, HCM, high-risk non-cardiac surgery, high anaesthesia risk score and intraoperative duration of hypotension were independently associated with 30-day composite events (p<0.05). Conclusions Patients with HCM undergoing high-risk and intermediate-risk non-cardiac surgeries have a low perioperative event rate, at an experienced centre. However, they have a higher risk of composite events versus matched patients without HCM.

Prevalence of Tibial Artery and Pedal Arch Patency by Angiography in Patients With Critical Limb Ischemia and Noncompressible Ankle Brachial Index

Background— Approximately 20% of patients undergoing ankle brachial index testing for critical limb ischemia have noncompressible vessels because of tibial artery calcification. This represents a clinical challenge in determining tibial artery patency. We sought to identify the prevalence of tibial artery and pedal arch patency by angiography in these patients. Methods and Results— One hundred twenty-five limbs (of 89 patients) with critical limb ischemia and ankle brachial index ≥1.4 who underwent lower extremity angiograms within 1 year were included. Reviewers of angiography were blinded to results of physiological testing. Tibial artery vessels were classified as completely occluded, significantly stenosed (≥50%), or patent (<50% stenosis). The sensitivity of toe brachial index and pulse volume recording to predict tibial artery disease was also determined. Of 125 limbs with noncompressible ankle brachial index, 72 (57.6%) anterior tibial and 80 (64%) posterior tibial arteries were occluded. Another 23 (18.4%) anterior tibial and 13 (10.4%) posterior tibial arteries had ≥50% stenosis. Pulse volume recording was moderate to severely dampened in 54 of 119 (45.4%) limbs. Toe brachial index <0.7 was found in 75 of 83 (90.4%) limbs. Moderate to severe pulse volume recording dampening was 43.6% sensitive, whereas toe brachial index <0.7 was 89.7% sensitive in diagnosing occluded or significantly stenotic tibial artery disease. The pedal arch was absent or incomplete in 86 of 103 (83.5%) limbs. Conclusions— Among patients with critical limb ischemia and noncompressible ankle brachial index results, the prevalence of occlusive tibial and pedal arch disease is very high. Toe brachial index <0.7 is more sensitive in diagnosing occluded and significantly stenotic tibial artery disease in these patients compared with ankle pulse volume recording.

Spontaneous renal artery dissection in a cannabis user

A 32-year-old previously healthy male presented to the emergency department with acute onset of right-sided abdominal and back pain. Review of his social history was positive for heavy daily cannabis use. Unenhanced abdominal computed tomography (CT) showed possible pyelonephritis that prompted treatment with oral antibiotics. After 7 days of persistent hypertension and pain, a followup contrast-enhanced abdominal CT revealed areas of infarction in the right kidney (Panel A). Duplex ultrasound confirmed decreased parenchymal flow with a monophasic pattern in the upper pole of the right kidney (Panel B). An abdominal aortogram demonstrated a perfusion defect in the same region (Panel C, dashed outline). Selective angiography of the right superior hilar artery confirmed the presence of a complex dissection extending into the distal segment (Panel D). Endovascular intervention was attempted, but the guidewire could not advance beyond the zone of dissection (asterisk). Intravascular ultrasound (IVUS) (Volcano Corporation; inset) with color imaging (ChromaFlo ® ) demonstrated a dissection flap with flow in both true (T) and false (F) lumens (entire IVUS recording available as a supplemental video). Extensive serological testing found no evidence of known coagulopathies or vasculitides. Intracranial and

PREVALENCE OF TIBIAL ARTERY AND PEDAL ARCH PATENCY BY ANGIOGRAPHY IN PATIENTS WITH CRITICAL LIMB ISCHEMIA AND NON-COMPRESSIBLE ABI (≥1.4)

Many patients with critical limb ischemia (CLI) have non-compressible ankle brachial index (ABI), believed to be due to vessel calcification. We sought to identify the prevalence of tibial artery and pedal arch patency by angiography in these patients. 125 limbs (of 89 patients) with CLI and ABI

TEMPORAL CHANGES IN LEFT VENTRICULAR STRAIN VIS-À-VIS EJECTION FRACTION IN PATIENTS WITH TAKOTSUBO CARDIOMYOPATHY

Vast majority of patients with Takotsubo cardiomyopathy (TC) demonstrate an improvement in left ventricular ejection fraction (LVEF) over time. LV global longitudinal strain (GLS) is a more sensitive marker of regional myocardial mechanics than LVEF. We sought to assess the temporal changes in GLS

Authors' Reply to "Anatomic Twist to a Straightforward Ablation"

We appreciate the thoughtful comments of Dr. Chase, Dr. Devi A and Dr. John regarding our case report of a patient who underwent AV junction ablation via a congenitally abnormal venous system. Our patient had an interrupted inferior vena cava with continuation as the azygos vein which drained into the superior vena cava, and ablation was successfully performed with the ablation catheter taking this circuitous route, through a long SRO sheath.