Sudden cardiac death in patients with hypertension. An association with diuretics and beta-blockers?

Association between serum potassium and risk of all-cause mortality among chronic kidney diseases patients: A systematic review and dose-response meta-analysis of more than one million participants

We aimed to perform a meta-analysis, using prospective cohort studies, to test the association between serum potassium and all-cause mortality among chronic kidney diseases (CKD) patients. A systematic search was performed using PubMed-MEDLINE and Scopus, up to July 2020. Prospective cohort studies which reported risk estimates of all-cause mortality in CKD patients with different serum potassium levels were included in the present meta-analysis. Thirteen studies were included in the analysis. A nonlinear dose-response meta-analysis suggested that there is a J-shaped association between serum potassium levels and the risk of all-cause mortality, with a nadir at serum potassium of 4.5 mmol/L. Subgroup analyses indicated that the strength and shape of the association between serum potassium and all-cause mortality may be influenced by age. Our meta-analysis provides supportive evidence that there is a J-shape association between serum potassium and all-cause mortality among CKD patients.

The impact of serum potassium-influencing antihypertensive drugs on the risk of out-of-hospital cardiac arrest: A case-control study

AIMS

Sudden cardiac arrest (SCA) is a complex multifactorial event and most commonly caused by ventricular tachycardia/ fibrillation (VT/ VF). Some antihypertensive drugs could induce hypokalaemia or hyperkalaemia, which may increase susceptibility to VT/VF and SCA.

OBJECTIVE

To assess the association between different classes of antihypertensive drugs classified according to their potential impact on serum potassium levels and the occurrence of out-of-hospital cardiac arrest (OHCA) based on VT/VF.

METHODS

A case-control study was performed among current users of antihypertensive drugs. Cases were OHCA victims with electrocardiogram documented VT/VF drawn from the AmsteRdam REsuscitation STudies (ARREST) registry, and controls were non-OHCA individuals from the PHARMO database. Antihypertensive drugs were classified into: (i) antihypertensives with neutral effect on serum potassium levels; (ii) hypokalaemia-inducing antihypertensives; (iii) hyperkalaemia-inducing antihypertensives; (iv) combination of antihypertensives with hypo- and hyperkalaemic effects.

RESULTS

We included 1345 cases and 4145 controls. The risk of OHCA was significantly increased among users of hypokalaemia-inducing antihypertensives [adjusted odds ratio (OR) 1.39; 95% confidence interval (CI) 1.10-1.76] and among users of a combination of antihypertensives with hypo- and hyperkalaemic effects (adjusted OR 1.42; 95%CI 1.17-1.72) vs. users of antihypertensives with neutral effect. There was no difference in OHCA risk between users of hyperkalaemia-inducing antihypertensives vs. users of antihypertensive drugs with neutral effect (adjusted OR 1.15; 95%CI 0.95-1.40).

CONCLUSION

The risk of OHCA is significantly increased in patients who were current users of hypokalaemia-inducing antihypertensives and patients using a combination of antihypertensives with hypo- and hyperkalaemic effects.

Evidence-based diuretics: focus on chlorthalidone and indapamide

Thiazide and thiazide-like diuretics are cornerstone treatments for hypertension. However, unlike chlorthalidone (CTD) and indapamide (IDP), hydrochlorothiazide (HCTZ) lacks evidence for reducing morbidity and mortality as monotherapy compared with placebo or control. Despite this fact, HCTZ is prescribed much more frequently than CTD or IDP. We believe that all hypertension guidelines should follow the National Institute for Health and Excellence (NICE) and make IDP and CTD first choice 'thiazide-like diuretics.' This article will focus on the available evidence pertaining to HCTZ versus CTD and IDP. We will review the pharmacological differences between these three diuretics, as well as the clinical trial data and important side effects.

Serum potassium and outcomes in CKD: insights from the RRI-CKD cohort study

BACKGROUND AND OBJECTIVES

The relationship between serum potassium (S(K)) and mortality in chronic kidney disease (CKD) has not been systematically investigated.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined the predictors and mortality association of S(K) in the Renal Research Institute CKD Study cohort, wherein 820 patients with CKD were prospectively followed at four US centers for an average of 2.6 years. Predictors of S(K) were investigated using linear and repeated measures regression models. Associations between S(K) and mortality, the outcomes of ESRD, and cardiovascular events in time-dependent Cox models were examined.

RESULTS

The mean age was 60.5 years, 80% were white, 90% had hypertension, 36% had diabetes, the average estimated GFR was 25.4 ml/min per 1.73 m(2), and mean baseline S(K) was 4.6 mmol/L. Higher S(K) was associated with male gender, lower estimated GFR and serum bicarbonate, absence of diuretic and calcium channel blocker use, diabetes, and use of angiotensin-converting enzyme inhibitors and/or statins. A U-shaped relationship between S(K) and mortality was observed, with mortality risk significantly greater at S(K) < or = 4.0 mmol/L compared with 4.0 to 5.5 mmol/L. Risk for ESRD was elevated at S(K) < or = 4 mmol/L in S(K) categorical models. Only the composite of cardiovascular events or death as an outcome was associated with higher S(K) (> or = 5.5).

CONCLUSIONS

Although clinical practice usually emphasizes greater attention to elevated S(K) in the setting of CKD, our results suggest that patients who have CKD and low or even low-normal S(K) are at higher risk for dying than those with mild to moderate hyperkalemia.

Increased Occurrence of Out‐of‐Hospital Cardiac Arrest on Mondays in a Community‐Based Study

Acute myocardial infarction and sudden cardiac death are more common on Mondays than other days of the week. The stress of returning to work at the beginning of the week has been postulated as a possible trigger factor. This project examined the weekly variation of out-of-hospital cardiac arrests of nontraumatic origin for the entire case series as well as for selected subgroups. A retrospective analysis of 1,498 incidences between January 1, 1995 and December 31, 1996 revealed a distinct Monday peak in occurrence irrespective of age, gender, presence of witnesses, primary survival, or primary ECG. This finding, however, was most pronounced in retired patients, subjects living alone, and persons found unconscious outside buildings or in public places. One important trigger of cardiac arrest is going to work after weekends; however, resumption of social and other activities on Mondays is another possible trigger. Other factors, such as endogenous biological rhythms, may contribute to an increased risk at this particular time even in elderly.

Metabolic side effects and cardiovascular events of diuretics: should a diuretic remain the first choice therapy in hypertension treatment? The case of yes

Essential hypertension is a major cause of cardiovascular morbidity and mortality in the Western world. Numerous clinical trials have demonstrated that the treatment of hypertension results in a substantial reduction of hypertension-related morbidity and mortality. The efficacy and safety of diuretics has been shown in many clinical trials. Like most other antihypertensive agents, the side effects of diuretics are mostly benign and mild. The metabolic side effects of diuretics, however, have been a bone of contention for a long time. In this paper, we describe the most important and frequent metabolic side effects of diuretics, and emphasize particularly the non-life-threatening effect of diuretics on ventricular arrhythmias due to their hypokalemic effect, the detection of the new onset diabetes (perhaps caused by the administration of diuretics itself), and their significant beneficial effect on cardiovascular and cerebrovascular morbidity and mortality. At the end of the article, we highlighted the differences regarding the prescription of diuretics between the recently published American and European Guidelines of hypertension.

Thiazide diuretic prescription and electrolyte abnormalities in primary care

AIMS

Thiazide diuretics have a number of well-documented metabolic adverse effects. The aim of this study was to estimate the frequency of hyponatraemia and hypokalaemia amongst patients taking a thiazide diuretic in primary care.

METHODS

A computerized search of the electronic prescribing and laboratory records of six UK general practices was performed. Of the 32 218 adult patients identified, 3773 had received at least one prescription for a thiazide between the years 1990 and 2002.

RESULTS

Detailed prescribing data were available for 2942 patients of whom 951 (32.3%) had a recorded check of their electrolytes. One hundred and ninety-six (20.6%) had a sodium and/or potassium concentration below the normal range. The sodium distribution had a negative skew (-1.8) and in 130 (13.7%) patients was within the hyponatraemic range. Hypokalaemia was less common, occurring in 79 (8.5%) patients. Hyponatraemia was significantly associated with increased age; the odds ratio for developing hyponatraemia in patients over 70 years was 3.87 compared with those of < or = 70 years. Hypokalaemia was significantly associated with increased thiazide dose.

CONCLUSIONS

Prescription of a thiazide diuretic in primary care is associated with a high frequency of hyponatraemia and hypokalaemia. Thiazides should be prescribed at low dose and the risk of hyponatraemia, especially in the elderly, should be considered and monitored for when prescribing these agents.

Hypokalemia associated with diuretic use and cardiovascular events in the Systolic Hypertension in the Elderly Program

The treatment of hypertension with high-dose thiazide diuretics results in potassium depletion and a limited benefit for preventing coronary events. The clinical relevance of hypokalemia associated with low-dose diuretics has not been assessed. To determine whether hypokalemia that occurs with low-dose diuretics is associated with a reduced benefit on cardiovascular events, we analyzed data of 4126 participants in the Systolic Hypertension in the Elderly Program (SHEP), a 5-year randomized, placebo-controlled clinical trial of chlorthalidone-based treatment of isolated systolic hypertension in older persons. After 1 year of treatment, 7.2% of the participants randomized to active treatment had a serum potassium <3.5 mmol/L compared with 1% of the participants randomized to placebo (P<0.001). During the 4 years after the first annual visit, 451 participants experienced a cardiovascular event, 215 experienced a coronary event, 177 experienced stroke, and 323 died. After adjustment for known risk factors and study drug dose, the participants who received active treatment and who experienced hypokalemia had a similar risk of cardiovascular events, coronary events, and stroke as those randomized to placebo. Within the active treatment group, the risk of these events was 51%, 55%, and 72% lower, respectively, among those who had normal serum potassium levels compared with those who experienced hypokalemia (P<0.05). The participants who had hypokalemia after 1 year of treatment with a low-dose diuretic did not experience the reduction in cardiovascular events achieved among those who did not have hypokalemia.