Ventilation-perfusion scan for diagnosing pulmonary embolism: do chest x-rays matter?

BACKGROUND

Ventilation-perfusion (V/Q) scan coupled with single photon emission computed tomography (SPECT) is commonly used for the diagnosis of pulmonary embolism (PE). An abnormal chest x-ray (CXR) is deemed to hinder the interpretation of V/Q scan and therefore a normal CXR is recommended prior to V/Q scan.

AIMS

To determine if an abnormal CXR impacted on V/Q scan interpretation and subsequent management.

METHODS

A retrospective cohort analysis of all patients who underwent a V/Q scan for diagnosis of suspected acute PE between March 2016 and 2022 was performed. CXR reports were reviewed and classified as normal or abnormal. Low-dose computerised tomography was routinely performed in patients above the age of 70. Data regarding V/Q scan results and subsequent management including initiation of anticoagulation for PE or further diagnostic investigations were collected.

RESULTS

A total of 340 cases were evaluated. Of the positive V/Q scans (92/340), 98.3% of the normal CXR were anticoagulated compared to 100% of the abnormal CXR group. Of the negative V/Q scans (239/340), no cases were started on anticoagulation and no further investigations were performed across both normal and abnormal CXR groups. Indeterminate results occurred in only 9 cases with no significant difference in management between normal and abnormal CXR groups.

CONCLUSION

An abnormal CXR does not affect the reliability of V/Q scan interpretation in the diagnosis of PE when coupled with SPECT. Unless clinically indicated, the mandate by clinical society guidelines for a normal CXR prior to V/Q should be revisited.

The utility of delta troponin in diagnosing significant coronary artery disease in patients with symptomatic atrial fibrillation

BACKGROUND

Troponin I (cTnI) elevation is common in patients with atrial fibrillation (AF) but does not reliably indicate underlying coronary ischemia. We investigated whether dynamic changes in cTnI value (delta troponin) are useful in revealing significant coronary artery disease (sCAD) in patients presenting with symptomatic AF.

METHODS

We conducted a retrospective case-control study analyzing serial cTnI values in 231 patients presenting with symptomatic AF who had an objective assessment for underlying CAD within 6 months of the index admission. Diagnostic performance of an elevated cTnI (>0.04 μg/L) only, and elevated cTnI coupled with Youden Index derived cutoffs for absolute and relative changes in troponin, for distinguishing patients with sCAD, was evaluated.

RESULTS

A total of 107 patients had an elevated cTnI on serial measurements. In this group, the area under the receiver operating characteristic curve was 0.69 [95% confidence interval (CI), 0.56-0.81] for relative delta troponin and 0.71 (95% CI, 0.59-0.83) for absolute delta troponin. The optimal diagnostic cutoff for relative delta troponin was > -0.42, and > -0.055 μg/L for absolute delta troponin. The specificity of elevated troponin to diagnose sCAD increased from 56 to 77% when relative delta troponin was added, and to 88% with absolute delta troponin. Although the sensitivity of cTnI elevation (57.1%) decreased to 50% for relative and 35.7% for absolute delta troponin, the negative predictive values were high and similar at 86%.

CONCLUSION

When added to the troponin peak, delta troponin is a promising test for the diagnosis of significant coronary artery disease in patients presenting with symptomatic AF with elevated cTnI. This result requires prospective validation in a larger cohort of patients.

Long-Term Survival, Stroke Recurrence, and Life Expectancy After an Acute Stroke in Australia and New Zealand From 2008-2017: A Population-Wide Cohort Study

BACKGROUND

Data on long-term outcomes following an acute stroke are sparse. We assessed survival, risk of recurrent stroke and loss in life expectancy following an acute stroke using population-wide data from Australia and New Zealand.

METHODS

We included all adults with the first stroke hospitalization during 2008 and 2017 at all public and most private hospitals. Patients were followed up to 10 years after the stroke by linkage to each region's Registry of Deaths and subsequent hospitalizations. Flexible parametric survival modeling was used to estimate all-cause mortality, stroke recurrence, and loss in life expectancy. Competing risk model was used when estimating the risk of stroke recurrence.

RESULTS

Three hundred thirteen thousand one hundred sixty-two patients were included (mean age 73.0±14.6 y, 52.0% males) with ischemic stroke (175 547, 56.1%) being the most common, followed by hemorrhagic stroke (77 940, 24.9%) and unspecified stroke (59 675, 19.1%). The overall survival probability was 79.4% at 3 months, 73.0% at 1 year, 52.8% at 5 years, and 36.4% at 10 years. Cumulative incidence of stroke recurrence was 7.8% at 3 months, 11.0% at 1 year, 19.8% at 5 years, and 26.8% at 10 years. Hemorrhagic stroke was associated with greater mortality (hazard ratio, 2.02 [95% CI, 1.99-2.04]) and recurrent stroke (hazard ratio, 1.63 [95% CI, 1.59-1.67]) compared with ischemic stroke. Female sex (hazard ratio, 1.10 [95% CI, 1.09-1.11]) and increasing age (≥85 years versus 18-54 years: hazard ratio, 7.36 [95% CI, 7.15-7.57]) were also associated with increased mortality. Several risk factors including atherosclerotic coronary and noncoronary vascular disease, cardiac arrhythmia, and diabetes were associated with increased risk of mortality and recurrent stroke. Compared with the general population, an acute stroke was associated with a loss of 5.5 years of life expectancy, or 32.7% of the predicted life expectancy, and was pronounced in patients with a hemorrhagic stroke (7.4 years and 38.5% of predicted life expectancy lost).

CONCLUSIONS

In this population-wide study, death and recurrence of stroke were common after an acute stroke and an acute stroke was associated with considerable loss in life expectancy. Further improvements in treatment and secondary prevention of stroke are needed to reduce these risks.

Sustained resolution of anticoagulation related iron deficiency anemia with the use of apixaban

Successful resolution of iron deficiency anemia in the context of anticoagulation with rivaroxaban was seen when apixaban is used alternatively. Prospective cohort studies utilizing similar or different approaches are required.

Split-dose bowel preparation with polyethylene glycol for colonoscopy performed under propofol sedation. Is there an optimal timing?

OBJECTIVE

Aspiration risk, especially with propofol sedation, remains a concern after split-dose bowel preparation of up to 1 L polyethylene glycol for the procedure. We aimed to identify the ideal timing of bowel preparation to achieve optimal colon cleansing with no increased risk of aspiration.

METHODS

A total of 892 consecutive patients undergoing simultaneous esophagogastroduodenoscopy (EGD) and colonoscopy were prospectively recruited. Residual gastric volume (RGV) and pH of gastric contents were measured at EGD, and patients' characteristics, runway time (duration between completion of the final liter of bowel preparation and colonoscopy commencement), and cleansing quality were recorded.

RESULTS

A shorter runway time resulted in better colon cleansing (r = -0.124, P < 0.001). No correlation between runway time and RGV or pH was found (r = -0.017, P = 0.62 and r = -0.030, P = 0.47, respectively). RGV and pH did not differ significantly with runway time of 4 or 5 h. RGV with runway time ≤3 h was 35.9 ± 11.8 mL and 17.4 ± 0.6 mL after runway time >3 h (P < 0.001). No aspiration pneumonia occurred. The only factors independently related to higher RGV were younger age and male sex.

CONCLUSIONS

The consumption of bowel preparation agent within 3-4 h before propofol sedation resulted in a similar RGV and pH as those achieved by more prolonged fasting, with no increased risk of aspiration even in patients perceived to be at high risk.

Predictors of significant coronary artery disease in atrial fibrillation: Are cardiac troponins a useful measure

BACKGROUND

Cardiac Troponin I (cTnI) is frequently measured in patients presenting with symptomatic atrial fibrillation (AF). The significance of elevated cTnI levels in this patient cohort is unclear. We investigated the value of cTnI elevation in this setting and whether it is predictive for significant coronary artery disease (sCAD).

METHODS

We conducted a retrospective, single-center, case-control study of 231 patients who presented with symptomatic AF to The Prince Charles Hospital emergency department, Brisbane, Australia between 2006 and 2014. Patients who underwent serial cTnI testing and assessment for CAD were included. Clinical variables that are known to predict CAD and could potentially predict cTnI elevation were collected. Binary logistic regression was performed to identify predictors of sCAD and cTnI elevation.

RESULTS

Cardiac Troponin I elevation above standard cut off was not predictive for sCAD after adjustment for other predictors (OR 1.62, 95% CI 0.79-3.32. p=0.19). However, the highest cTnI concentration value (cTnI peak) was predictive for sCAD (OR 2.02, 95% CI 1.02-3.97, p=0.04). Dyspnea on presentation (OR 4.52, 95% CI 1.87-10.91, p=0.001), known coronary artery disease (OR 3.44, 95% CI 1.42-8.32, p=0.006), and ST depression on the initial electrocardiogram (OR 2.57, 95% CI 1.11-5.97, p=0.028) predicted sCAD in our cohort, while heart rate on initial presentation was inversely correlated with sCAD (OR 0.99, 95% CI 0.971-1.00, p=0.034).

CONCLUSION

Troponin elevation is common in patients presenting to hospital with acute symptomatic AF and it is not a reliable indicator for underlying sCAD in this patient cohort. However, cTnI peak was a predictor of significant coronary artery disease.