P. Foëx

Predictors of postoperative myocardial ischaemia. The role of intercurrent arterial hypertension and other cardiovascular risk factors.

One hundred and eighty‐three patients were studied to examine the role of a number of risk factors in the development of silent ischaemia after general anaesthesia for general and vascular surgery. We collected evidence of cardiovascular risk factors using a binary questionnaire. The patients were monitored pre‐ and postoperatively using a Holter ECG monitor. Usable data were collected on 140 patients. Pre‐operative silent myocardial ischaemia was found to be strongly associated with postoperative silent myocardial ischaemia (odds ratio: 10.8, 95% confidence intervals: 3.8–30.7). A history of hypertension, indicated by treatment with antihypertensive drugs, was associated with increased risk (odds ratio: 2.58, 95% confidence intervals: 1.12–5.96). A linear trend was found for risk associated with increasing admission systolic blood pressure (odds ratio: 1.20 for each 10‐mmHg increase in systolic pressure, 95% confidence intervals: 1.01–1.42). An association between vascular surgery and postoperative silent myocardial ischaemia was also confirmed (odds ratio: 2.36, 95% confidence intervals: 1.1–5.1).

Statin therapy: a potentially useful peri-operative intervention in patients with cardiovascular disease

Statin cardiovascular protection is mediated by lipid lowering and pleiotropic effects. The efficacy of statins has been established in non‐surgical patients with cardiovascular disease and also more recently in non‐surgical patients who sustain an acute coronary event. Peri‐operative statin administration has been shown to improve both short‐term and long‐term cardiac outcome following non‐cardiac and coronary bypass graft surgery. This cardioprotection may be independent of peri‐operative haemodynamics due to a positive effect on plaque stability. Recommendations for the peri‐operative statin administration are suggested. These include indications for peri‐operative statin therapy, timing of administration, therapeutic targets, duration of administration, the adverse implications of peri‐operative statin withdrawal, safety and cost‐effectiveness.

Increases in serum concentrations of cardiac proteins and the prediction of early postoperative cardiovascular complications in noncardiac surgery patients

We investigated the use of measurements of serum concentrations of the cardiac proteins troponins I and T as biochemical markers of myocardial cell damage in 80 patients undergoing vascular or major orthopaedic surgery. Holter electrocardiographic monitoring was carried out before surgery and for 3 days after surgery. Blood samples for troponins I and T and creatine kinase‐MB isoenzyme were taken on each of these 4 days. Outcome was assessed at 3 months using a patient questionnaire, general practitioner follow‐up and case notes review. Silent postoperative myocardial ischaemia was detected in 21 patients; increases in troponins I and T and creatine kinase‐MB occurred in four, six and 17 of these patients, respectively. Eight patients suffered major postoperative complications (cardiac death, myocardial ischaemia, congestive cardiac failure, unstable angina and cerebrovascular accident) and 21 minor complications (poorly controlled hypertension needing increased or new additional treatment, palpitations, increased tiredness or shortness of breath in the absence of known respiratory disease). There were no associations between postoperative ischaemia and cardiac protein concentrations. The relative odds for the associations of major adverse outcome at 3 months after surgery and postoperative ischaemia or increased serum concentrations of the three proteins were 5.39 [95% confidence intervals 1.16–27.67] for postoperative ischaemia; 5.64 [1.07–31.00] for creatine kinase‐MB isoenzyme; 17.00 [2.20–116.54] for troponin T and 13.20 [1.12–135.00] for troponin I. We found troponin T to be the only prospective marker for both major and minor cardiovascular complications (relative odds 10.65 [1.26–252.88]).

Peri-operative troponin I concentration as a marker of long-term postoperative adverse cardiac outcomes - A study in high-risk surgical patients

We have previously demonstrated that the peri‐operative measurement of increased serum concentrations of the cardiac markers troponins I and T and creatine kinase‐MB can be predictors of major cardiovascular outcomes (including cardiac death) at 3 months after surgery. In the present study, we have followed the postoperative course of 157 patients undergoing major vascular surgery or major joint arthroplasty to 1 year using a patient questionnaire, general practitioner follow‐up and case‐notes review. Increased postoperative marker concentrations were defined as values greater than the upper reference limit. Increases in troponin I and troponin T concentrations, as well as a single elevated creatine kinase‐MB and two successively elevated creatine kinase‐MB concentrations were measured in 12, 13, 33 and 15 patients respectively. Thirty‐nine major adverse cardiac outcomes were recorded (cardiac death, myocardial ischaemia, congestive cardiac failure, unstable angina, cerebrovascular accident and major arrhythmias needing active treatment). There was no association between increases in any of these cardiac markers and cardiac death to 1 year. However, increases in troponin I and both a single elevated creatine kinase‐MB and two successively elevated creatine kinase‐MB concentrations were associated with an increased incidence of major cardiac outcomes, including cardiac death, to 1 year (odds ratio [95% confidence intervals] = 4.19 [1.16–14.87], 3.97 [1.65–9.44] and 5.19 [1.60–16.22], respectively).

Effect of chronic β-blockade on peri-operative outcome in patients undergoing non-cardiac surgery: an analysis of observational and case control studies

Little is known about the effect of chronic β‐adrenoceptor antagonist therapy during the peri‐operative period in patients undergoing non‐cardiac surgery. We conducted a literature review to identify studies examining the relationship between chronic therapy and adverse peri‐operative outcome. Eighteen studies were identified in which it was possible to ascertain the incidence of adverse cardiac outcomes in those patients who were and were not receiving chronic β‐blocker therapy. None of the studies demonstrated a protective effect of chronic β‐blockade. The results of these studies were then combined and a cumulative odds ratio calculated for the likelihood of myocardial infarction, cardiac death and major cardiac complications. Patients receiving chronic β‐blocker therapy were more likely to suffer a myocardial infarction (p < 0.05). These findings differ from the published effects of acute β‐blockade. Reasons for this discrepancy are considered.

Peri-operative silent myocardial ischaemia and long-term adverse outcomes in non-cardiac surgical patients.

Two hundred and seventy‐five non‐cardiac surgical patients were recruited to determine risk factors associated with the development of postoperative cardiovascular complications during the first year after surgery. Patients underwent ambulatory electrocardiography pre‐ and postoperatively. There were 34 adverse events over the whole study period. Twenty‐four occurred within 6 months and the remaining 10 occurred between 6 and 12 months postoperatively. Silent myocardial ischaemia was associated with adverse outcome over both the first 6 months [OR 4.44 (95% CI 1.77–11.13)] and the whole study period [OR 2.81 (1.26–6.07)]. Other risk factors were: vascular surgery [OR 17.09 (2.67–351.44)], history of angina [OR 6.29 (2.21–17.62)], concurrent treatment with calcium entry blockers [OR 2.68 (1.03–6.93)] and smoking [OR 4.93 (2.00–12.02)]. None of these was a useful predictor of long‐term outcome (between 6 and 12 months postsurgery). These results are at variance with other published data, but we conclude that monitoring for peri‐operative silent myocardial ischaemia does not aid the prediction of long‐term cardiovascular complications.

The pharmaco-economics of peri-operative statin therapy

We analysed the pharmaco‐economics of the prospective peri‐operative studies of statin administration for major elective vascular surgery, using the NHS reference costs for 2004. This analysis suggests that peri‐operative statin therapy for patients undergoing vascular surgery may present the most cost‐effective use of statin therapy yet described, with a number‐needed‐to‐treat of 15 and almost 60% of the total cost of atorvastatin therapy recovered through a reduction in peri‐operative adverse events.

Silent myocardial ischaemia in patients undergoing transurethral prostatectomy

Ninety four patients undergoing transurethral resection of the prostate underwent Holter electrocardiographic monitoring pre‐and postoperatively. There was no difference in silent myocardial ischaemia incidence or load between the spinal (n = 60) ami the general anaesthesia (n = 34) groups. Ischaemic heart disease and a higher Detsky score both significantly increased the incidence of silent myocardial ischaemia but not the ischaemic load of those patients that actually demonstrated ischaemia. In this specific surgical population, not undergoing cardiac or vascular surgery, both ischaemic heart disease and cardiac risk scores are poor predictors of ischaemic load. Merely the presence of short duration silent myocardial ischaemia probably has little predictive value for postoperative adverse outcome.

Beta-blocker use in severe sepsis and septic shock: a systematic review

Abstract Objective: Recent growing evidence suggests that beta-blocker treatment could improve cardiovascular dynamics and possibly the outcome of patients admitted to intensive care with severe sepsis or septic shock. Design: Systematic review. Data sources: MEDLINE and EMBASE healthcare databases. Review methods: To investigate this topic, we conducted a systematic review of the above databases up to 31 May 2015. Due to the clinical novelty of the subject, we also included non-randomized clinical studies. We focused on the impact of beta-blocker treatment on mortality, also investigating its effects on cardiovascular, immune and metabolic function. Evidence from experimental studies was reviewed as well. Results: From the initial search we selected 10 relevant clinical studies. Five prospective studies (two randomized) assessed the hemodynamic effects of the beta1-blocker esmolol. Heart rate decreased significantly in all, but the impact on other parameters differed. The imbalance between prospective studies’ size (10 to 144 patients) and the differences in their design disfavor a meta-analysis. One retrospective study showed improved hemodynamics combining metoprolol and milrinone in septic patients, and another retrospective study found no association between beta-blocker administration and mortality. We also found three case series. Twenty-one experimental studies evaluated the hemodynamic, immune and/or metabolic effects of selective and/or non-selective beta-blockers in animal models of sepsis (dogs, mice, pigs, rats, sheep), yielding conflicting results. Conclusions: Whilst there is not enough prospective data to conduct a meta-analysis, the available clinical data are promising. We discuss the ability of beta blockade to modulate sepsis-induced alterations at cardiovascular, metabolic, immunologic and coagulation levels.

Peri‐operative silent myocardial ischaemia in patients undergoing lower limb joint replacement surgery: an indicator of postoperative morbidity or mortality?

One hundred and twenty‐seven patients undergoing major lower limb joint replacement surgery were studied to determine the incidence of silent myocardial ischaemia and to ascertain any link between pre‐operative cardiac risk factors, silent myocardial ischaemia and postoperative morbidity. Patients underwent ambulatory ECG monitoring for 4 days (on the pre‐operative night and for 3 days postoperatively). Postoperative cardiorespiratory symptomatology and morbidity was assessed by questionnaire at 3 months. Eighty‐seven patients had risk factors for silent myocardial ischaemia; 42 patients (30 with risk factors) had peri‐operative silent myocardial ischaemia. The median ischaemic loads (range) were 1.04 (0.32–13.31) min.h−1 pre‐operatively and 5.53 (0.26–56.39), 6.69 (0.04–42.71) and 1.23 (0.1–53.74) min.h−1 on postoperative days 1–3, respectively. Risk factors did not predict the occurrence of silent myocardial ischaemia or an increased ischaemic load pre‐operatively or overall postoperatively. New symptoms (chest pain, palpitations, breathlessness or fatigue) were associated with both silent myocardial ischaemia and ischaemic load (p < 0.05). Thus cardiac risk factors do not predict the occurrence of silent myocardial ischaemia or adverse outcome. Peri‐operative silent myocardial ischaemia was associated with increased postoperative fatigue.