Exercise Capacity and Ventilatory Response During Exercise in COPD Patients With and Without β Blockade

Background

Although β blockade (BB) in patients with chronic obstructive pulmonary disease (COPD) does not show signs of worsening pulmonary function or respiratory symptoms, the effects on cardiopulmonary exercise testing (CPET) remain unclear. The aim of this study was to determine whether BB affects exercise capacity, gas exchange, and hemodynamic responses in patients with COPD.

Methods

Twenty-four COPD subjects on BB were matched to 24 COPD subjects without BB according to age, gender, body mass index, and severity of COPD. All subjects underwent resting pulmonary function and symptom-limited CPET.

Results

Comparing COPD patients with and without BB revealed that percent peak oxygen consumption and VE/VCO₂ nadir were not significantly different (45 ± 16 vs. 51 ± 23 %, p = 0.30, and 35.1 ± 8.5 vs. 36.2 ± 11.6 %, p = 0.69). Systolic blood pressure and heart rate at peak exercise were significantly decreased in COPD patients with BB (168 ± 16 vs. 185 ± 20 mmHg, and 109 ± 16 vs. 122 ± 14 bpm, respectively, p < 0.05).

Conclusion

Exercise capacity and gas exchange remain unaffected in patients with COPD in the presence of BB, although heart rate and blood pressure are lower. These findings imply that BB does not adversely affect functional capacity in patients with COPD.     

When and How Should We Revascularize Patients With Atherosclerotic Renal Artery Stenosis?

Atherosclerotic renal artery stenosis is the leading cause of secondary hypertension and may lead to resistant (refractory) hypertension, progressive decline in renal function, and cardiac destabilization syndromes (pulmonary edema, recurrent heart failure, or acute coronary syndromes) despite guideline-directed medical therapy. Although randomized controlled trials comparing medical therapy with medical therapy and renal artery stenting have failed to show a benefit for renal artery stenting, according to comparative effectiveness reviews by the Agency for Healthcare Research and Quality, the trials may not have enrolled patients with the most severe atherosclerotic renal artery stenosis, who would be more likely to benefit from renal stenting. Because of limitations of conventional angiography, it is critical that the hemodynamic severity of moderately severe (50% to 70%) atherosclerotic renal artery stenosis lesions be confirmed on hemodynamic measurement. The authors review techniques to optimize patient selection, to minimize procedural complications, and to facilitate durable patency of renal stenting. The authors also review the current American College of Cardiology and American Heart Association guidelines and the Society for Cardiovascular Angiography and Interventions appropriate use criteria as they relate to renal stenting.     

Imaging Patients With Kidney Disease: How Do We Approach Contrast-Related Toxicity?

The approach to imaging patients with kidney disease with iodinated radiocontrast and gadolinium-based contrast has changed dramatically in recent times. The complications of these contrast agents, radiocontrast nephropathy and nephrogenic systemic fibrosis, respectively, underlie the changes in the imaging practice used in these patients. Rather than to completely avoid the use of these contrast agents, one must remain judicious in the choice of imaging modality in this group of patients. A prudent approach would be to (1) identify patients at high risk to develop contrast-related complications, (2) use noncontrast-based imaging techniques in these patients, as long as they are suitably diagnostic and safe and (3) if the risk:benefit ratio of the imaging information favors a contrast-based study, then appropriate prophylactic steps and use of contrast agents with the lowest risk of complication should be used after obtaining informed consent. This will allow one to maximize the diagnostic efficiency while also limiting the adverse effects.     

Primary Anastomosis or Hartmann’s Procedure for Patients With Diverticular Peritonitis? A Systematic Review

PURPOSE This systematic literature review was designed to summarize and compare the reported outcomes of one-stage and two-stage operations for the treatment of perforated diverticulitis with peritonitis.METHODS This review identified 98 published studies (1957–2003) dealing with the surgical management of perforated diverticulitis with peritonitis, either with primary resection and anastomosis or with the Hartmanns procedure. Aggregated results of adverse outcomes were calculated but statistical comparisons were not appropriate because of data and design heterogeneity.RESULTS Operative mortality data from patients with diverticular peritonitis undergoing Hartmanns procedure (n = 1,051) were derived from 54 studies. Considering the Hartmanns procedure and its reversal procedures together, the mortality rate was 19.6 percent (18.8 percent for the Hartmanns procedure and 0.8 percent for its reversal), the wound infection rate was 29.1 percent (24.2 percent for the Hartmanns procedure and 4.9 percent for its reversal), and stoma complications and anastomotic leaks (in the reversal operation) occurred in 10.3 and 4.3 percent, respectively. Of 569 reported cases of primary anastomosis from 50 studies, the aggregated mortality rate was 9.9 (range, 0–75) percent with an anastomotic leak rate of 13.9 (range, 0–60) percent and a wound infection rate of 9.6 (range, 0–26) percent.CONCLUSIONS Reported mortality and morbidity in patients with diverticular peritonitis who underwent primary anastomosis were not higher than those in patients undergoing Hartmanns procedure were. This suggests that primary anastomosis is a safe operative alternative in certain patients with peritonitis. Despite inclusion of only patients with peritonitis in this analysis, selection bias may have been a limitation and a prospective, randomized trial is recommended.Reprints are not available.     

Laparoscopic Colorectal Resection in Octogenarian Patients: Is it Safe? A Systematic Review and Meta-Analysis

The population older than 80 years has been increasing. A significant proportion of colorectal diseases that require colorectal resection occur in very elderly patients. However, the benefits of laparoscopy remain controversial in octogenarians. A systematic review and meta-analysis of observational study was performed to compare clinical outcomes between laparoscopic versus open colorectal resection in octogenarians.The PubMed, EMBASE, Ovid, Web of Science, and Cochrane databases from the years 1990 to 2015 were searched for studies that compare surgical outcomes between laparoscopic and open colorectal resection in octogenarians (≥80 years old).Seven eligible studies including 528 laparoscopic and 484 open colorectal resections were identified. Laparoscopic approach was associated with lower rate of mortality (odds ratio [OR] 0.48, P = 0.03), overall complications (OR 0.54, P < 0.001), and prolonged ileus (OR 0.56, P = 0.009), quicker bowel function return (standardized mean difference [SMD] −0.50, P < 0.001), and shorter length of hospital stay (SMD −0.47, P = 0.007). No differences were found in anastomotic leak (OR 1.16, P = 0.72), respiratory complication (OR 0.60, P = 0.07), and reoperation (OR 0.85, P = 0.69).Laparoscopic colorectal resection is as safe as open approach, and the short-term outcomes appear to be more favorable in octogenarians.     

Can Medications be Safely Withdrawn in Patients With Stable Chronic Heart Failure? Systematic Review and Meta-analysis

BackgroundHeart failure (HF) therapy involves use of multiple medications. There is little guidance on the safety and impact on clinical outcomes of stopping HF medications.Methods and ResultsA comprehensive systematic search for studies of drug therapy withdrawal in HF was performed. Meta-analysis of the risk ratio (RR) was performed with the use of the Mantel-Haenszel random effects model for all-cause mortality and cardiovascular outcomes. Twenty-six studies met the inclusion criteria. Studies on withdrawal of renin-angiotensin-aldosterone system (RAAS) inhibitors and beta-blockers in HF are scarce and small, yet show relatively convincingly that such withdrawals have untoward effects on cardiac structure, symptoms, and major outcomes. Meta-analysis of 7 studies of digoxin withdrawal (2,987 participants) without background beta-blocker showed increased HF hospitalizations (RR 1.30, 95% confidence interval [CI] 1.16–1.46; P < .0001), but no impact on all-cause mortality (RR 1.00, 95% CI 0.90–1.12; P = .06) nor reduction in all-cause hospitalization (RR 1.03, 95% CI 0.98–1.09; P = .27). Diuretic withdrawal trials demonstrated an ongoing need for these agents in chronic HF. Studies in peripartum cardiomyopathy showed that medications could be successfully withdrawn after recovery.ConclusionCurrent evidence discourages any attempt to discontinue RAAS inhibitors or beta-blockers in patients with stable HF, regardless of clinical and/or echocardiographic status. Formal withdrawal trials of other classes are needed.     

Should We Optimize Cardiac Resynchronization Therapy During Exercise?

Should We Optimize CRT During Exercise? Cardiac resynchronization therapy aims at diminishing cardiac dyssynchrony in patients with heart failure. The effect of cardiac resynchronization therapy can be improved by optimization of the atrioventricular (AV) and interventricular (VV) delays. Currently, optimization of these pacing settings is mainly performed during resting conditions. This paper aims to objectively review the current literature about a rate‐adaptive AV and VV delay in cardiac resynchronization therapy. The current evidence for a rate‐adaptive AV and VV delay comprises only small nonrandomized studies on acute effects. The effect of exercise on the optimal AV delay was heterogeneous between studies. The optimal VV delay was influenced by exercise conditions in some, but not all patients. Possible explanations lie in the heterogeneous electrical and mechanical responses to exercise in patients with a complex disease such as heart failure with asynchronous contraction. Current evidence is insufficient to show the superiority of a rate‐adaptive AV or VV delay in all CRT patients. Individualized exercise programming may be warranted in selected patients. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1307‐1316, November 2010)     

Colorectal Cancer Localization in Young Patients: Should We Expand the Screening Program?

We sought to investigate the frequency and distribution of colorectal cancer (CRC) in patients by age and to evaluate whether there is a difference between young (<40 years of age) and older patients (≥40 years of age) with regard to cancer localizations. From a total of 5165 colonoscopies, 314 (6.0%) cases were identified to have colorectal carcinoma. Forty-one (13%) of 314 CRC patients were young, with a mean age of 31.1±5.7 years. When cancer localizations were compared with reference to age, it was seen that CRCs in young patients were mostly localized at the right colon, versus at the left colon and rectum (P=013) in patients >40 years of age. Tumor localizations in colon cancer patients change with age. In our study, young patients tended to have right-sided colon tumors, but those in patients >40 years of age were frequently localized at the left colon and rectum.