Questions from NEJM Resident Bulletin Flashcards
Updates in Internal Medicine
_ was an international, open-label, multicenter randomized trial that compared everolimus-eluting stents with coronary-artery bypass grafting (CABG) in patients with left main coronary artery disease.
EXCEL (Evaluation of XIENCE versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization)
How are patients with obstructive left main coronary artery disease usually treated?
CABG - high morbidity and mortality owing to the large amount of myocardium at risk. - European and U.S. guidelines: most patients with left main disease undergo CABG.
In what subgroup of patients with left main coronary artery disease might PCI be an acceptable alternative to CABG?
low or intermediate anatomical complexity, - Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX): Composite outcome similar in paclitaxel-eluting stents and CABG. - outcomes of PCI acceptable only in the patients low or intermediate anatomical complexity
Is PCI noninferior to CABG for left main coronary artery disease of low or intermediate anatomical complexity?
Yes - EXCEL trial, PCI with everolimus-eluting stents was noninferior to CABG with respect to the primary composite end point of death, stroke, or myocardial infarction at 3 years. -The primary composite end-point event of death, stroke, or myocardial infarction at 3 years occurred in 15.4% of the patients in the PCI group and in 14.7% of the patients in the CABG group (difference, 0.7 percentage points; upper 97.5% confidence limit, 4.0 percentage points; P=0.02 for noninferiority; hazard ratio, 1.00; 95% confidence interval [CI], 0.79 to 1.26; P=0.98 for superiority). The relative treatment effect for the primary end point was consistent across prespecified subgroups, including the subgroup defined according to the presence versus absence of diabetes.
Cardiology.valvular-heart-disease.AS.TAVR
Is TAVR widely used for patients with aortic stenosis who are at high surgical risk?
Rapid adoption
The adoption of TAVR in patients with aortic stenosis at high risk for surgery has been rapid, The comparative efficacy of TAVR and surgery has been less well studied among patients with aortic stenosis who are at lower surgical risk.
Hence Reardon:
Reardon et al. conducted a study that compared the safety and efficacy of transcatheter aortic-valve replacement (TAVR) performed with the use of a self-expanding bioprosthesis with surgical aortic-valve replacement in patients who were deemed to be at intermediate risk for surgery. The mean age of the participants was 79.8±6.2 years, and most had coexisting illnesses.
(Data:Society of Thoracic Surgeons–American College of Cardiology Transcatheter Valve Therapy Registry.
Cardiology.valvular-heart-disease.AS.TAVR
How does transcatheter aortic-valve replacement compare to surgical replacement for intermediate-risk patients with severe aortic-valve stenosis?
Non-inferior to surgery
Reardon et al. found that TAVR was statistically noninferior to surgery in patients who were deemed to be at intermediate surgical risk by a multidisciplinary heart team. The primary end point was a composite of death from any cause or disabling stroke at 24 months. The incidence of the primary end point at 24 months was 12.6% in the TAVR group and 14.0% in the surgery group (95% credible interval [Bayesian analysis] for difference, −5.2 to 2.3%; posterior probability of noninferiority, >0.999). At 24 months, the rate of death from any cause was 11.4% in the TAVR group and 11.6% in the surgery group (95% credible interval for difference, −3.8 to 3.3%); the rate of disabling stroke was also similar in the two groups.
Cardiology.valvular-heart-disease.AS.TAVR
What were some of the other outcomes in the trial by Reardon et al.?
Paravalvular regurgitation more common in TAVR
Early (≤30 day) acute kidney injury stage 2 or 3 and new or worsening atrial fibrillation occurred more often in the surgery group than in the TAVR group, whereas major vascular complications and the need for permanent pacemaker implantation occurred more often in the TAVR group. Transfusions were more common in the surgery group than in the TAVR group, including an increase by a factor of 3.5 in the need for four or more red-cell units. Aortic-valve hemodynamics improved in both the TAVR group and the surgery group. The TAVR group had lower mean aortic-valve gradients and larger aortic-valve areas than did the surgery group. Moderate or severe residual paravalvular regurgitation was more common in the TAVR group at 1 year (5.3% in the TAVR group vs. 0.6% in the surgery group; 95% credible interval for difference, 2.8 to 6.8%).
Oncology.spinal-metastases
What primary tumors are associated with spinal epidural metastases?
- Breast
- Prostate
- Lung
- NHL
- RCC
- MM
Breast, prostate, and lung cancers are frequent causes of metastasis to the vertebral column, but non-Hodgkin’s lymphoma, renal-cell cancer, and myeloma are also common causes. In some instances, the primary tumor cannot be identified. In children, sarcoma, neuroblastoma, and lymphoma have been reported as the most frequent causes of spinal cord compression.
Oncology.spinal-metastases
What types of spinal epidural metastases are responsive to radiotherapy?
Lymphoma, myeloma, and seminoma
- Treatment by XRT and surgical decompression is partly palliative, but relief of paraplegia and pain are possible for considerable periods.
- Definitive treatment is guided by the extent of compression, by the stability of the spine, and by the responsiveness of the tumor to radiation.
- Lymphoma, myeloma, and seminoma: highly responsive and are treated with radiotherapy almost independently of the degree of cord compression.
- Breast, prostate, and ovarian: varied but intermediate responses to radiotherapy and are considered for surgery, although they may be treated with XRT.
- NSCLC, renal, thyroid, and gastrointestinal cancers, as well as sarcoma and melanoma, are relatively radioresistant and are treated with surgery, but some data support the use of conventional radiotherapy or radiosurgery.
ID.spinal-epidural-abscess
Features
- High rate of delayed diagnosis
- Presentation: abrupt or indolent
- Cord compression due to: mechanical, infarction
- Most affected: thoracic spine
- Commonest pathogen: Staph; 50% MRSA
- Range of pathogens including anaerobes
A. Bacterial infection of the spinal epidural space is a treacherous condition with a high rate of delayed diagnosis. The myelopathy of epidural abscess may appear abruptly or remain indolent for weeks. Mechanical compression of the spinal cord occurs as a result of the mass effect of the infectious collection, but vasculitic infarction has also been implicated. The thoracic spine is most often affected, and abscesses usually occupy several contiguous or noncontiguous levels of the spine. Bacterial infection at a site distant from the spine is found in only half of affected patients, and one fourth have no primary infection, even at autopsy. Diabetes, in particular, but also cancer, immunosuppression, renal failure, and intravenous drug and alcohol abuse are underlying conditions. Staphylococcus aureus, evenly distributed between methicillin-resistant and methicillin-sensitive organisms, is the most common pathogen cultured from the abscess or blood, but a range of bacteria are found, including anaerobes.
Cardiology.coronary-artery-disease
Can CAD regress?
A 42-year-old man with hyperlipidemia and a family history of coronary artery disease presented with a 4-month history of intermittent exertional chest pain. Myocardial perfusion imaging performed during exercise showed moderate ischemia in the distribution of the left circumflex coronary artery (Panel A, arrow). Coronary computed tomographic angiography (CTA) revealed a large amount of atherosclerotic plaque in the proximal left circumflex coronary artery, which had resulted in severe stenosis (Panel B, arrow). The patient was treated for chronic stable angina with high-intensity statin therapy, ezetimibe, a beta-blocker, and aspirin; he was advised to adopt a healthy diet and to engage in regular physical activity. Over time his symptoms resolved. Four years later, he reported the onset of atypical chest pain. Repeat myocardial perfusion imaging showed no myocardial ischemia (Panel C, arrow), and repeat coronary CTA showed a marked reduction in the amount of plaque and the severity of stenosis in the left circumflex coronary artery (Panel D, arrow). The CTA results were reassuring that his current symptoms were not cardiac. These imaging findings suggest that even when severe stenosis is present, coronary artery disease can regress with medical therapy.
GI
is the most common congenital malformation of the gastrointestinal tract, and if the diverticulum contains ectopic or heterotopic mucosa, it can cause gastrointestinal bleeding. It is located on the antimesenteric surface of the mid-ileum, and represents persistence of a proximal part of the vitelline duct (omphalomesenteric duct). In contrast to the mucosal herniation through the bowel wall that is present in diverticular disease, it contains all three layers of bowel wall.
Meckel’s diverticulum
GI.Meckels-diverticulum
Where is it located and what does it represent embryologically?
- Located on the antimesenteric surface of the mid-ileum
- Represents persistence of a proximal part of the vitelline duct (omphalomesenteric duct).
GI.Meckels
What causes the bleeding associated with a Meckel’s diverticulum?
Ectopic gastric mucosa
Acid-producing ectopic gastric mucosa in the diverticulum, causing an ulcer in adjacent normal mucosa. The ulcer can be present in the diverticulum itself but is usually located at the junction of the diverticulum and the ileum.
GI.Meckels
Dx and Rx
- Technetium-99m pertechnetate scan
- Essential to remove all ectopic gastric mucosa, (cannot be reliably detected from the outside).
What is the appropriate diagnostic imaging test for suspected Meckel’s diverticulum?
A. Technetium-99m pertechnetate normally accumulates in any gastric mucosa, including ectopic gastric mucosa; therefore, this radiotracer is useful in the evaluation of a suspected Meckel’s diverticulum. Technetium-99m pertechnetate is excreted by the urinary system, and activity is normally seen in the bladder and kidneys. Bowel or urinary activity is suggested by movement of focal radiotracer activity over time, whereas the focal accumulation in a Meckel’s diverticulum should remain fixed in position. A lateral view of the abdomen can be helpful in distinguishing urinary activity in the ureters, which are located in a posterior position. A false positive scan can result from inflammation, intussusception, bowel obstruction, or vascular lesions. A false negative scan can result from the presence of too little or no gastric mucosa in a Meckel’s diverticulum; approximately 20% of Meckel’s diverticula do not contain gastric mucosa.
Figure 1. Technetium-99m Pertechnetate Scan of the Abdomen.
Q. What are the surgical options for a Meckel’s diverticulum that causes gastrointestinal bleeding?
A. A variety of operations can be performed to treat a Meckel’s diverticulum that causes gastrointestinal bleeding. These include simple diverticulectomy, wedge resection of the diverticulum and the small cuff of adjacent ileum at its base, and segmental small-bowel resection. Although removing both the ectopic mucosa and the ulcer would seem to be the best approach, removing the ectopic mucosa alone may be sufficient, since the ulcer would probably then heal. However, it is essential to remove all ectopic gastric mucosa, which cannot be reliably detected from the outside. Therefore, a reasonable approach is to perform a simple diverticulectomy for a diverticulum with a narrow base but to perform a wedge or segmental resection for a diverticulum with a broad base, since ectopic tissue may be left behind if the diverticular base is not fully excised.
